Ever had ur baby name taken?

My hubby and I had a set girls name for approx 5 years... One we loved and every time we heard it gave a secret knowing smile to each other that one day we would have a daughter with that name. Until 18 months ago his sister had a baby girl and freakishly chose the name. We had never told anyone.... I always said if she had somehow picked it it would be a fluke and we would be unlucky that we had the same taste in names however if we had told and they used it I'd be hurt...

Now... Fast forward 18 months, after a mc, we have been TTC for 8 months and ever since that name was used when our neice was born have had another girls name we were set on. 

My sister is now pregnant and just told us she plans on using that particular name!!!! (It is a name in our family so we were dreading this!)

I'm slightly devistated!!! Why does this keep happening especially when they are not common names? Anyone else been in this position? I feel like we can't say oh that was going to be ours as she is pregnant and I'm not. Any tips on how to cope with this again?!