Sexing Boesemani Rainbowfish

[Botanica]

Hi everyone! So...my husband and I are trying to have a nice shoal of Boesemanis with about 5 males and 3 females...however... The employees at our LFSs aren't very reassuring when they've chosen our fish. We currently have 12 of them...7 we bought originally and...silly me...I forgot to ask about male/female. When we got them into their new home and were watching them get settled in...I began to notice that they all had the same shape...more or less. One was twice as big as the others...but she was older. I went online and read tons of info...looked at tons of photos...and still couldn't decide. Two days ago we were in a different LFS and they were offering what appeared to be "obvious" males for a great price...being so small...so we asked for 5 males. Now we have 12 total and seeing them all together...I still don't know...lol! There are two different shapes...so that's good. I have come to the conclusion that we are just going to have to wait and see what's what when they grow up.

Having said all that...and thanks for reading!...what I need to know is how long usually until they are fully grown?

I am attaching a few photos I have managed to catch of them in focus if anyone has an opinion. . Thanks!