My prayers for you and your girlfriend. I have one such mother as you have described, yet she just doesn't go so far as to set me up with other people, she simply disapproves either verbally or by ignoring the situation entirely.
I'm sure your girlfriend doesn't agree with the things her mother is doing, so I pray her mother will come to realise that she can not lead her daughters life for her and that her daughter is happy where she is now. With you
Once again, my unworthy but understanding prayers