Tip the seamstress?

I think this is the same as other vendors. If they own their own business, a tip isn't expected, if they work for someone else, you should tip.

I was going to tip mine but that is because I think she is not charging me what she should be charging me and she hemmed a sundress for me as well without charging extra.

I am not as she owns her own business.

I bought my dress from David's so no.