In your situation, yes, I'd use the name.
To the bigger question, it's kind of an "it depends". In general, I didn't even consider names that had already been used.
But my maiden name is a somewhat popular boys name. I had always talked about how,if/when I had kids, I wanted to incorporate my maiden name.
Well before I ever got PG, a friend told me that her DH liked an extended version of my maiden name and he wanted to name their son that and call him by the nick name, which would have been my maiden name.
Now, she didn't want to use that name at all, regardless of it being "my" name, but she told her DH they couldn't use it because it was "mine".
I told her very honestly that I didn't care- they could use it. But it wouldn't have stopped me from using it!
I never planned on using it as a first name (it's now DS's MN) - but regardless, it really literally was "my" name and someone else using it wouldn't have stopped me from using it.