Hmmm .... flexibility can be a mixed bag. I say that as someone who is hyper flexible. Its more important to balance strength and flexibility, and it is a balancing act. Pun intended. When I increased flexibility faster than strength, I started having more balance problems and more injuries for hiking, strength is more critical than flexibility when it comes to balance, as I understand it. Any pt's reading this who can confirm or negate this?
Flexibility helps when it comes to peeing and pooping in the wild. And it is useful when climbing, where the more flexibility you have, the more choices for foot and hand holds.
I really recommend an evaluation of the balance problem.
And bringing self awareness into any practice you undertake. By that, I mean, don't just take yoga classes and do what you are told. Pay attention to your own goals. If a class seems to be more focused on flexibility than strength and /or balance, back off on pushing flexibility until your strength catches up. Or add weight training to the mix, with emphasis on leg strength.