For a mutation:
What if there is a female lion, but the mane is fuller like any regular male, unlike the slight manes that are in the game right now! I did some research and some articles say that when lionesses get manes sometimes they act more like males! The mutation appears at the 1 year as a light mane and grows into a full mane like males as suggested by The Dirt King (#113702) in the first comment!

The effects could be that she could be a broodmother, go on patrols, and hunt(uncertain about the hunting part still) but a downside would be that she is infertile and chasteberries do not work!(suggested by The Dirt King (#113702) The infertile part would make the mutation harder to pass. The patrolling and hunting would make the mutation actually useful for a change (sorry but I mean like we should have at least one useful mutation right?) Also maybe the mutation could be genetic and it would be more passable with males that have CERTAIN BREEDING ONLY MANE TYPES! (this would make manes useful also!) If they had manes and had some cubs maybe their cubs could have a higher survival rate because lionesses with manes actually help scare off some predators! (see resource 3)

Sorry if this was already suggested but I spent lots of time and effort coming up with this and typing it all out! This idea might be hard on Xylax and the other team members but I think it would be really nice to have a mutation that does something more than kinda just sit there :P (I know not all mutations are like this but still!)

Rescources: (they mostly say the same thing but still! You may research some more and comment what you think!
1-https://www.newscientist.com/article/2106866-five-wild-lionesses-grow-a-mane-and-start-acting-like-males/
2-https://www.sciencealert.com/these-five-lionesses-have-grown-manes-and-now-they-re-starting-to-act-like-males
3-https://www.sciencealert.com/why-do-these-lionesses-in-botswana-have-manes
4-https://www.snopes.com/lionesses-grow-manes/

If you do not support i would like to hear why so then I can improve this >~<