I completely agree with Lee - you can't force her to take her meds unless she is on a treatment order. Have you tried talking to her about your concerns and how you are feeling? Maybe she hasn't thought about or noticed the changes. I know sometimes when I am unwell (or becoming unwell) I don't always notice and need someone else to point out the signs.

You can always talk to her doctor as well to let them know and they can try to talk to her about it.