I would stick with very gentle massages and also show her some good stretches to put everything back where it belongs. The overstretched muscles are weakened - they need to be worked to stretch the tightened muscles. The two of you can do those stretches together and then she can continue to work on her own. A chiropractor may be needed to adjust the spine, but it won't work or help if everything is still very tight. Do you know any chiros that work well with the elderly? Some are very good with them, while others tend to be too forceful. Ask around before referring. You don't want her to break, or to feel so much worse (even on the way to getting better) that she decides it's better left alone.
Unfortunately, doctors tend to be very quick to drug the elderly, and very rarely listen or dig to find a cause.
Has she quit sitting in that recliner? Seems like a silly question, but it's very important!! She needs to evaluate how she sleeps, too. If she sleeps on her side with her head drooping, that needs to change. Postures in daily activities will all contribute to either getting better or getting worse.