Guppy fry growth question

So I have a small tank and I bought some teensy guppy fry last month. Never had guppies before. Just wanted to check and see if they are normal.

December 6th

Today

SOME of them are beginning to grow cute little tails... Just wondering if their growth rate is okay. I have a habit of underfeeding my fish so IDK.

They look normal to me, But that tank will be to small for them. They need space to grow & need to be fed at least 3 times a day for decent growth rate

Some of mine......7 weeks old, Fed 4 times a day with Crushed Flake, Live & Frozen foods. These are kept in a 10 Gallon tank with constant temp at 25oC

I have a 10 gallon but REALLY did not want to use it yet. The Rasbora in there I still have to figure out what to do with him.

The problem is they grow reasonably quick & need a lot more room. Also depending what sexes you have, The females will breed. So if you have say 10 young & out of that half are females then the multiplier gets stupid. 5 Females having 10 fry each.....i wont do the maths cos im sure you get my meaning. But then their youngster fry will breed also, See what i mean?
But putting this aside a 10 Gallon could safely be home for maybe 7-8 adults of mixed sex but then there is still the breeding to think of. Males are sexually mature at 8 weeks. All the females will be pregnant at 12-14 weeks old, Rough guess yours look a few weeks older than mine