I wouldnt worry about the fry too much. I had 2 guppies which became
one. The female that was left behind kept producing babies long after
the male was gone. I guess she stored the 'good stuff' for a rainy
day. I finally ended up putting her in a bucket of water...and
now...many moons later, there are about 30-40 of them in the bucket. I
noticed that feeding the fish regularly and keeping the water fresh =
more guppies.

Good luck.