Okay so turns out I was pretty good with the pregnancy judgement, placed her in the trap around 11pm last night and came home from school today (about 4pm) to find a much less inflated fish!.... and 5 babies! Wait.... 5? 5!? hmm..... at first I thought the mother might have eaten them, but then I looked closer...
So after counting again, and again.... and again.... I watched as one of these five tiny babies literally slipped out through one of the gaps in the net's mesh, floated down to the bottom corner of the tank, and went straight into the filter intake!!
So I quickly attached a large sponge to the end of the pipe, hoping to save any other survivors.
But this seriously restricted flow, to a pretty much non-existent level...

So I ended up finding an old stocking and tightly covering the intake with that, seems to have done the job! I also found two more babies hiding down around the new twisted val, and watched them pick about for food for a while. They seem to be doing well and avoiding the adults well.
But this leaves me with a problem, I now have 2 that could potentially be eaten at any moment and another 4 that could potentially escape the net and face the same fate...
In relation to your comment about the breeding nets and the frame snazy, not once, not twice but three times I watched a baby find its way through a hole in the mesh, get stuck in between the mesh and the glass, and then have to release it down and into the tank attempting not to hurt it... very frustrating.
What are my alternatives to this net? If I had a heater I'd be able to raise them straight away in my 10 gal but right now it would probably drop to about 15C at night, far too cold. Should I try to make some sort of similar thing with a cup and stocking? Should I leave them to roam the tank?