Sorry for your loss, always terrible when they sneak out on us. A shame you didn’t had more time together. Don’t let this encourage you from this beautiful hobby.
When did she show for the first time restless behavior? My first guess is she is in her receptive phase at the moment and is still developing eggs. The second restless period is mostly the one she's looking for place to lay her eggs.
Agree with @LizardLurkin and wanted to ask the same. And...
Assumption it’s her first time? My girls first time was a hell and took ages. Was also afraid she would become egg bound. I would give her a bit more time and privacy, nature do her thing.
The poor thing looks maybe a bit thin, but with a good new loving home, a bit of dedication and the correct husbandry, I think savable. IMHO worthy doing it. At least at first glance no signs of MBD, which would be a good thing.
Giving them a chance and saving them from their poor start of...