Common misconceptions: This is a choice. It's not. DID and other personality disorders come from trauma and stress, and are not a grab for attention. Both of the people I know developed these things after a traumatic event, and this event also boosted their chronic depression.
There is no limit to alters. They can come in any shape or size, and as many as they want. They can have different pronouns, attitudes, and even ages.
It's not black and white. Alters come and go and return in a tornado sometimes. There can be multiple alters in "control" at once, and sometimes you can't tell who's leading.
No alters alter the same. Some hosts refer to themselves as multiple people, and others are just one, it depends. Always be open and accepting, and be ready to be corrected, since you'll probably get it wrong the first time.
THIS IS NOT SAYING THE TWO ARE DIRECTLY RELATED. DID and other personality disorders can be like genderfluidity (the way it is for me at least). One second you're sure who's leading, or what your pronouns are, the next you're going down rabbit holes and can't figure it out.
Like always, be a kind person and don't try to "fix" them. If they want help, they will reach out. Now, if they are in danger or a danger to others, step in, but don't try to change people into something they aren't.
Ill continue later but i gtg now. Bye!