Hi,
i doubt your daughter as ever suffered from depression herself - since she feels that depressed people can just snap out of the illness, when others want them to.
I would say that if she’s not happy with you being around the baby when you're depressed, then she should find an alternative carer for the baby. You can't just snap out of it and you are only going to become more depressed if you begin to stress and feel guilty, about the impact it might have on the baby.
In what ways are you coping with your depression?? Are you one medication, or receiving any counselling at all??
There are many ways to reduce depression such as a eating a healthy diet, exercise, doing something creative to express yourself - but the problem is that it can be very difficult to motivate yourself to do these things as they can take alot of effort for someone who is depressed. You could try making a list of things which may reduce depression, and try and make very small changes little by little so that it's not such a strain on you.
All the best