Financially, when is the best time to move your parent into assisted living?

Rae, sounds like it will be awhile before your Mom would need long-term-care unless a serious illness or injury sets in. Your profile says your Mom is in Independent Living already, so that is great. But you also wrote she will only have $50k at the end of the year. How long will the $50k last for Independent Living? Is that why you are wondering about long-term-care?

My Mom lived at home with my Dad until she was 98 and due to serious fall she was placed in long-term-care. Most of the patients in that unit were in need of serious caregiving.... many were either bedridden or in wheelchairs... some had major memory issues... some had serious illnesses. I think that is when the long-term-care insurance kicks in... but as Pam said, read the policy.

if she has 50 k i know a place where she can receive gourmet hog bones and beans and probably an occasional lower back massage .
thats 49 k more than i have , even counting my metric bolt / nut stash ..

Read your policy carefully. In Assisted Living, it may not cover room & board, just the level of care costs.
If she is still driving and doing her own cooking, I doubt if she is in need of long term care.