I would encourage you to switch. Mindfulness can be done alone and can be learned from books. However, to be really challenged requires another person to give input. The new therapist you liked may not be available forever (who knows) so I would give her a shot while you can.

I would agree with what Anastasia said. Just be honest, and tell your current therapist that although she has been very helpful and makes you feel really calm and good, you also want to try something new.