I understand Thai nurses in government hospitals are compulsorily retired at age 45, with a modest pension. They then find employment as carers with wealthier Thai families. Apparently the going rate is 10K - 15K baht/month.
Alternatively, look for a Thai lady in their 40's at a massage shop. They are going to be strong enough for most tasks. They don't earn much, and probably would jump at any salary more than 10K/month, although there may be more trust issues.
Obviously, the OP's capabilities in terms of communicating in Thai need to be considered.