Does a mod exist somewhere that allows intergender stables?

[chrisgoesover]

And the ability to access the intergender entrance animations?

[Cave Waverider]

You can use Data Editor to edit the .team_info and put mixed gender people into stables/teams and also set any entrance animation for them. Check out the Data Editor Tutorials for more information.
Alternatively, you can also use Data Editor's .pofo editor or CCT's quick actions to set your females to male (which will then even allow you to put them into any stable in-game) so you can have intergender in any match with the bonus that women can bleed when set to male, too (with the caveat that they will be referred by announcers as "he" and won't be able to contest for female only titles - although you can work around that by making a copy for males with the Create a belt feature or potentially change the gender bytes for these belts to male as well).

[chrisgoesover]

Thanks so much for your help! One more quick question - I’ve just gotten into PC 2K19, long time PS4 player and I remember that I couldn’t access the Mike and Maria entrance. Is it possible to assign that entrance to a team with this method? 

[Cave Waverider]

35 minutes ago, chrisgoesover said:

Thanks so much for your help! One more quick question - I’ve just gotten into PC 2K19, long time PS4 player and I remember that I couldn’t access the Mike and Maria entrance. Is it possible to assign that entrance to a team with this method? 

Yes. As long as you don't edit the entrance in-game afterwards, it will work fine.