I've asked Main Chat a few times for the rules on reverse studding a female but I haven't received notice of any topic existing (if it does please link me in a comment! Just one persons comment is good!)

However I think there should be a more formal way to reverse stud a female lion than sending items hoping the other person is honest and that you get the cubs. I reverse stud and I have reverse studded other females without a hitch however there is always the worry.

1. Placing a female up for reverse studding: like becoming a broodmother your lioness would be subjugated to being a reverse stud, whether she can still hunt or be a brood mother shouldn't be affected as it would be the same as if the main male of the account were to stud her.

2. So now she is a stud: Just like the main male of the pride she should get a little box separate from her biography portion, preferably above where the two boxes offer the Play and Breed option. This way you could adjust her breeding fee (say she is a leopon with her heat in auction, this way her breeding fee could be adjusted to the winning bid).

3. But the requests? What if she is a leopon? All the requests for her heat?!: Just like the main male is studded and receives a list of people who want to breed with him, she too would have a list of those who want to breed her. If her stud fee is set to 5gb and someone requests it at that price the stud fee cannot be adjusted until the request is rejected (meaning there must be no current requests in order to adjust the stud fee). This way the player can reject, adjust, and advertise their female for studding.

4. Who's the daddy?: Since it is often that reverse studding has Player 1 purchasing another Player 2's female studding, they tend to send the female to another Player 3's male for breeding and the resulting cubs are sent to the initial players account. This is very tricky and I am not sure how this would pan out.
Option 1: in purchasing player 2's female heat, Player 1 would need to purchase the studding as well. the option for stud would need to be sent to Player 3 via ID number. This cycle would work like so
-Player 1 requests Player 2's females heat
-Player 2 Confirms Player 1's request
-Player 2's confirmation would trigger a game notification of confirmation to Player 1
-Player 1 is meant to return to Player 2's female's page where the portion for stud request has altered in appearance: it now requests an Online Player's ID number to be entered.
-Player 1 may now enter an online studs ID(Player 3), the stud fee for the male would pop up next to the ID box
-In the event that Player 1 wants to stud the Female to their own male they would put in their own ID number and the fee would show as 0sb & 0gb.
-Player 1 can now send the stud request to Player 3.
-Player 1 cannot feed the lioness if she is hungry and cannot play with her (unless the two accounts are a part of the same clan and can then mood boost).
-Once pregnant Player 2's lioness cannot be traded or transferred until her cubs reach 5 months. At 4 months old Player 1 and Player 2 each receive a notification that the cubs will be automatically transferred to Player 1's account the following rollover. At 5 months The cubs are automatically transferred to Player 1's account and Player2's lioness is now available to be traded or transferred.
-While weaning the resulting cubs the participating female is able to hunt and broodmother other cubs. Player 2 does not have to assign the cubs to a broodmother(s).

5. Breeding items: Just like when a female is sent to a male for studding there is the option for him to eat some items. Items would be sent the moment the stud request to the male(Player 3) is sent and Player 1 is given the option to use fertility items on the participating Female or Male. For example send a lion scrote to the female and a grain of paradise to the male. Yohimbe barks would not apply as they are meant to reduce the females heat, this would all be taking place in 1 solid day.
-If Player 1 wished for the cubs to age and birth immediately, an Instant Cub Delivery feather could be sent by visiting the lionesses. The portion where reverse studding once had the request button, then the stud fee, would now show the option to IBF the Lioness. After being done if a cub was wanted immediately Player 1 could apply an aging stone to individual cubs who would be immediately transferred to Player 1's account.

6. Timing: The female can only be confirmed for breeding by Player 2 IF Player 1 is online at the time. The requested Female must be in heat at time of confirmation. The rest is up to Player 1 to iron out. If Player 1 cannot find an appropriate stud before the next rollover the process begins again for day 2 of the females heat, day 3 and then day 0.

My current dilemmas:
I don't know how the currency would work? What if Player 2 decided not to rollover while the cubs were weaning? If all payments are made directly after conception what about cub accident safety, making sure the lioness is 100% happy and full so the litter is not miscarried? Player 2 could theoretically send the earned currency to a different account and decide to not roll the account the pregnant lioness is on. What about all these different panels on the lioness's page that would be constantly changing with each step of the process, is there a way to make it easier? Potential bugs that might send lions to the wrong accounts?

Please give your opinions! This is a very big change and would take a long time to code I bet. I want to know what you think and what you would change. I have put a lot of thought into this so any critiques please be constructive!

Added Ideas only below this line will I edit.
1. Idea by Ladwik NPC that ensures the cubs age with or without the Player 2 rolling their account. (either in explore or in den)
-What if there was a stork of sorts (cause babies) that would watch over the cubs (in explore or you must purchase it for your den prior to putting any lioness up for reverse stud, say from Monkey Shop) and ensure the cubs and mother age accordingly. (cant just skip rolling the account so the cubs wean and leave the mother frozen)
2. Limit the amount of reverse studs you can have on a your account to 1 initially, but just like sub slots or frozen slots it can be unlocked for more available lionesses. (maybe the first unlock is 1000sb, second is 2gb, 3rd is 5gb, 10gb and so on) +a cooldown (how long? 1day/1week?) for addition and removal of the 'female stud' title