Abbey doesn't bother me, it's my cousin's name so I'm used to it as a full name.
It really depends on the name for me. I would never use
Ellie or
Katy /
Katie as full names, yet
Nora and
Kate are perfectly acceptable to me. Maybe it's the ee endings, though that doesn't make sense with
Abbey. I'll just say with
Abbey it's because I've grown up with a cousin my age named
Abbey and her name has grown with her. However,
Timmy is not a grown up name. I have two uncles named
Timothy. One was
Timmy for the longest time but once he was in his twenties he wanted to be
Tim or
Timothy. My other uncle is still
Timmy and it just seems very babyish for a grown man to be called
Timmy all the time.
I like when parents give their child a more formal name with different NN options. I love
Eleanor and
Katharine which have a plethora of NNs. That way the child can grow up to kind of pick their own or allow a NN to evolve. Then again, I still love
Nora and
Kate so I feel like I'm contradicting myself, lol.