The Five Love Languages principles are brilliant and definitely have helped some (mono) relationships I know. It could be something as simple as communicating in different love languages, which is relatively easy to fix.
But yeah, if she's going stircrazy because of a lack of work/life ambition I would get her out of the house and pursuing something she enjoys. Just because she's retired doesn't mean that she has to let go of ambition.
Don't fight against the existing model, create a new model that makes the old model obsolete.