Just a thought, I'm not 100% sure but I always thought you had to have some sort of substrate for cory's.
I've heard a few people on the forums saying you can get an api master kit on amazon for $20 to $30. Not a bad price considering over here they are nearly €50
She might just be bloated. I have a Dalmatian mollie here ready to pop, but I'm not set up for fry at the minute and going on honeymoon next week so I won't be able look after them, I'm afraid I'll just have to let nature take its course. There are loads of hiding spaces so a few might survive.
Are you keeping your tank bare bottom?
If not you're gonna have a little trouble when you do add substrate.
How are the new inhabitants getting on
Sorry I just saw reply now, I haven't been on her in a few days, busy with last minute wedding stuff.
Your ammonia looks good, coming down nicely, if I were you I would start checking for nitrite now, as they should be rising slightly if your ammonia is dropping.
Glad they are all doing well and no pregnancies!!
Mine had one or two fry so far that I have seen but I'd say they became a tasty snack?