i'd leave them be and encourage growth by feeding the anemone a piece of table shrimp or fresh fish (about the size of it's mouth), every 2nd - 3rd day. take the time to keep the clownfish and any ornamental shrimp or spider crabs from reaching in and taking it's morsel. peppermint and cleaner shrimp, etc., will reach into the mouth after it closes and pull out the morsel of food, they'll do the same with fungia plates. a well fed bta will grow relatively fast.
when i kept Entacmaea quadricolor i used to offer buyers their choice of clones, was often left with one very small one but it never took long for a 2"-3"er to grow to +10". given good conditions and feedings i'm confident your bta will be at least 5" by august. if not get another bta, some stay small in shallow waters and form large mats consisting of many individual bta's well others usually in deeper water remain solitary and grow rather large. my rbta's oral disc would max out at 15" - 18" before dividing but i've seen 24" rbta's.