How do I help my best friend escape her controlling mother?

Sad daughter against mother on sofa

DEAR DEIDRE: HOW do I help my best friend escape her controlling mother?

I’m 26, my friend is 27, and her mum is 56. We’ve been friends since we were young teens after meeting on our street.

Growing up, she was homeschooled and didn’t spend time with any other young people apart from me. 

While I realised her mum was a bit overbearing, it’s only since becoming an adult that I’ve realised how bad things actually are.