As I understand it, a child ABP cannot have its own ‘AnimGraph’; it must inherit from its parent. So, the structural logic of the ‘AnimGraph’ will be the same, but the sequences can be changed per child (using the overrides mentioned earlier). Only an ABP derived from ‘Anim Instance’ will have its own ‘AnimGraph’.
Your only alternatives are a ‘Linked Anim Graph’ or ‘Anim Layer Interface’; either way I suspect you would need retargeting as well for different skeletons.
Additionally, it may be possible to create your own parent class with C++. This link discusses the issue, and provides a link to some code for creating a custom ‘Anim Instance’ ABP:
Here are some other resources:
How to Animate Your Character - Linked Animation Graph (UE5)