She is having trouble with her inhaler which is prescribed 4X daily. For her it is normally 3X daily as she is only up for around 12 hours per day. (If she wakes in the night having trouble she will use it.) Whenever I show her how to use it she does fine but I'm beginning to think she is having trouble with her doses.
As far as I know, if you need someone who will measure out any medicine or pills and give them to her directly, it will have to be an RN.
As far as I know, Medicare only provides in-home care after a hospital stay - and only for a few weeks. (If your Mom qualifies for Medicaid, they may have different rules. Also, have you looked into veterans benefits, if applicable?)
And yes, you always need a doctor's order for any Medicare covered assistance. Check with your insurance - I will assume it is the same.
However, if you hire privately (out-of-pocket), you do not need "permission" from anyone. RNs cost more than CNAs or other paid caregivers.
good luck