so currently in verse twilight and pinkie have no children, while pinkie did want a herd but twilight doesnt feel like shes ready to take on parenthood yet. while it caused some minor turmoil between them, it ultimately wasnt enough to break what they had between them. pinkie is willing to wait as long as twilight needs, even if she wanted her own herd what matters more is her wifes comfort.
luckily pinke has gotten to help spike and gabby raise their son ken + babysit mauds daughter moon pie, she loves being the doting auntie and twilight loves seeing her wife so happy and in her element when shes with the kids.
pinkie helps twilight organize and keep things in check, she essentially fills in for spike when hes busy with his own life. not to say she doesnt have her own job, shes still a busy party planner. she no longer works full time at sugarcube corner, as sugar bell has taken over that role but when pound cake needs an extra hoof around the shop he calls up pinkie.
twilight on the other hand, is not princess of equestria as luna and celestia never stepped down. she currently balances being princess and principal of her school.
anyways sorry for sloppy writing i dont have the details perfectly ironed out but this is essentially what is going on!
sidenote: twipie is so underrated