The frog spawn may have not grown or grown any new heads or branches because its not getting the nutrition is needs. It may just be getting what it needs to survive and not thrive.
If your friends are wanting the frogspawn to grow they should first get a calcium test if they do not have one already, and test there calcium levels which should be between 450-500. closer to 450. If the calcium is low you can by a calcium supplement.
Also you can get a food like Kents microvert, thats what I use someone may tell you of a diffferent or better food. You can dose the tank or spot feed the coral directly. Be careful with this food overfeeding with it will degrade you water quality. Doing this should help the frog spawn show signs of growth with in a month or two. This and clean clean water.
HTH