Mollie questions

Okay so a few days ago I got 4 sailfin mollies(IDk wheather thier velifera or Latipinna) and I wanted to ask some questions. First, how fast do these guys grow? Right now they are between 1.5 and 2in in length. I have been feeding them New Life Spectrum and they just had thier first sprinula flakes today. Im going to start feeding them mysis shrimp tommorow. Should i feed them anything else? I know they like veggies in thier diet. Lastly, is it okay for them to be breeding at this size? I have 2 males and 2 females and the males are mating with them pretty often. Any other info would be nice.

Just to make the thread interesting I will add some bas quality pics. They are in a 29 gallon with 4 flier cichlids.