It may sound a little ridiculous but you should see if she’s open to edging without cumming.
My wife had a fairly low sex drive before trying it and we always thought it was because of medication too.
We added in an element of control where I would tell her how many times she needed to edge each day. To make it more fun I would hold something like a d4 and d6 in each hand. She would pick a hand, roll the die, and then edge that number of times during the day.
I would reward her good behavior by making her cum after we had sex. I would punish her bad behavior by holding higher numbers and/or spanking her.
We did that for a few months and her libido is much higher than before. I still control her orgasms and decide when she gets to cum but I don’t give her an edge quota anymore. She lets me fuck her whenever I want now and is very well trained. :)
I was inspired to try this after reading stories, often written by women, about how edging helped a lot with libido. Some women say that if they get all the way to the edge that it doesn’t help. They call that a hard edge and prefer to get themselves highly aroused without reaching the edge instead (soft edge).