I'm in a very similar situation to you. Although my loves are the ones with the children, not me, and I'm moving half way around the world. I WISH it were only 1800 miles.
I haven't told my parents yet. I plan to do so once it's been working for a few months. Good luck. You have to do what will make you happy. Hopefully once she sees how happy you and your daughter are, she will feel better and be happy for you.
"Thou art to me a delicious torment." - Ralph Waldo Emerson