Nice Job! To help the fry survive longer in the big tank, plant the tank densley with live or fake plants. The trick is to guess when the mother is going to give birth and then to put her into a breeding tank. Normally no one gets it right in their first go but after 2 or 3 times, you will notice how fat the fish are normally before they give birth. (remembering to mabey add a mm each time or so as the more times live bearers have birth, generally the more fish you get) although there are variables you must consider before that.
A few years back i bred about 300 guppys which kind of brought me into loving to keep fish. Every now and then i try to breed them and it is always great fun. I just set up a tank and am giving it a shot now.
You should try to breed swordtails too! Its quite funny watching them grow up in the breeding tank with the guppies. They grow in like 1/2 the time to the same size as the guppys and normally you can let out the swordtails into the main tank pretty quickly.
Hope you catch that houdini if a fry

and if you get more fry, feed them newly hatched live brine shrimp

they love it. There are hundreds of articles on how to make them and the hatchery but the general steps are: buy the eggs, fill the hatchery with salt water. I find 1 tablespoon (not teaspoon) of sea salt is adequate per litre. Then stick an airline in the tank on itsown without the diffuser thingy attached to it. leave it by the window (watch out for ledges which tilt at an angle. i got soaked the other day when i forgot and just so happened to be right next to it) Nehow, after 36 hours, cover up the hatchery for 10-15 mins and block air bubbling through. Syphen out the brine shrimp which have no settled a the bottom, rinse and feed (but dont overfeed) You might want a shrimp net, but a cotton handkerchief works well too, but rinse before
