Too deep of water for my baby RETF coming on Thursday?

[Heatheranne]

I have been playing around with my tank. I think this will be safer for my new baby to come.

I have also set up my 10 gal for her until I know she is healthy enough to join Stickers.

At what age will I be able to tell her sex?

I am purchasing him/her from joshsfrogs. He says it's too early to tell yet and that they are about 1 1/2 inches currently.

Stickers is approx. 3 inches.