What's in a name?

8 weeks along but of course hubby and I have been discussing baby names for a lot longer! We have a few picked out, but none of them feel "right" to me except for middle names, which are a sure thing. For a girl, the name I keep coming back to is Anna - simple, sweet, vintage. Here's the thing though: Anna is the name of my baby sister who died two days after her premature birth. This happened when I was in 2nd grade, so about 25 years ago. We all still grieve her death, more so like, "She'd be ____ years old now", "I wonder what she'd be like", etc. I'm a very sentimental person and to me, if we have a girl, naming her Anna would have so much meaning to me. I've been going back and forth on asking my mom if it's okay that if we have a girl, we name her Anna, but I also wanted to keep the name a secret. I don't know how to approach the subject, but is it even okay to consider Anna as a name?