That looks to be a full-size adult female. The only concern with a 90 gallon tank would be tankmates that are potential fin nippers.
Very pretty boy! What a nice display he made for your pics, the little showoff!
I have the same tank, currently empty except for some plants.
I have one very fat, bloated looking cherry barb in my 36 gallon. He's been looking somewhat explosive for a couple of months now. However other than
I rarely find the smaller fish after they've died, those MTS are very quick to take advantage of a nice snack like that.
I currently have 29 bunches and more coming!