
Sounds like you are doing fine! :)
Do exactly what you said by letting her get used gradually to you not being there.
Good way to do this is to have her in the crate (door closed so she cant wander off), then go into the kitchen or another room where she cant see you for 5 mins, then return and if she was good and quiet reward with a treat and let her out.
If you repeat this (Getting further and further away from her in her crate) and gradually increase the time by 5 mins each session, or when she has mastered the previous timeframe increase it as needed, she will eventually get the idea of she has to be alone and deal with it. As long as she has her favourite toy in there with her (not chews etc incase she has trouble with one and you are not there to help) she should be just fine!! :)
Goes for leaving the house as well, use the same method above and she will soon be used to it!