I was going to say it's definitely a case by case basis and what both parents and kids are comfortable with. With same-gender couples, I've often seen with my friends using two different gendered honorifics, like "mom" and "mama" or "dad" and "papa".
With trans people, often times it depends on when they came out. If before the child was born, or they were really young, I know a lot of parents will switch what they use, but for many people the title becomes something beyond gender. I've met a trans woman who transitioned later in life and was still "dad" to her kids because her role as a dad didn't invalidate her gender as a woman. In the same vein, I've known nonbinary folk who have kept "mom" or "dad" after coming out, went with a less traditional title, or even just made one up either something fun and ungendered (think something like "babi"). I've also heard people just using a diminutive of they're name, like rather than the kid saying "my parent, Sam" it becomes "my Sammy".
The fun thing about language is that it changes to fit the needs of people and groups, so we can just make it up as we go!
Only one party does that lol