Livebearers Interbreeding?

Question
I have two female Mollies, a mother and a daughter. This daughter was the sole survivor of mom's first litter, born in February (we were on vacation and another female ate almost all the fry born between the two of them). We have not bred her since.
We separated both into a ten gallon tank before Baby was one week old.
I have recently moved the two of them, as well as my Guppies and Neon Tetras and Otocinclus, into my forty gallon. Suddenly, Baby is looking pregnant. I wondered, "Could a Guppy have gotten her pregnant?" Surely not! we thought. They're both livebearers, but they're not the same. Surely they cannot breed! She is just a pig and gorges herself everyday.
But she still looks pregnant. It's been almost a solid week of her looking swollen to the point of bursting. Two days ago I thought I saw tiny eyes showing through.

Is this possible? Can she be pregnant? Or was our first thought correct, and she is just ridiculously fat? Maybe she has some sort of parasite in there? She acts so healthy though..

Answer
Hi Teneisha

Guppies and Mollies will breed. I've seen pictures of fry from a Male Molly & Female Guppy cross.. however they did not survive. In fact, in the articles I read, very few of these fry survived from a cross male to female or female to male. Those that did survive, had genetic defects.

So if she is pregnant from the Guppy, I doubt the fry will live long.

Hope this helps, good luck!

Richard