Yes, it's hard when anyone WE love refuses to acknowledge the choices we make in our lives that we feel will lead to happiness and being the best we can be. But this seems to be part of the necessary break we all make with parents and start becoming our "selves". It happens in many small ways - not always a big & dramatic as this, but there's a host of other scenarios that are equally as big & dramatic that people seem to go through.
To me it's seems the important point is to navigate this with love. Continue to express the same love to your Mum as you would otherwise - regardless of her approval or acceptance. Try to teach by example. Live genuinely & lovingly. In time she may see the results of what was initially beyond her comprehension. And her view may change. Seen this many times
If her love for you is genuine and she sees that your actions are bringing positive results in your life......well, you can't argue with facts.