I would get it done now. My second DD has a very mild tounge tie that was only noticed at her 6wks check when I told the Dr she had one. He didn't think it was bad enough to snip it at the time as she was feeding fine and could stick out her tounge. BUT fast forward over 4 years later and she is seeing a speech therapist and some of her issues with forming sounds are directly related to her tounge tie. Especially any sounds that require her to put her tounge to the roof of her mouth, like the 'L' sound. If I had of known then what I know now I would have asked the Dr to snip it.