With cards I use to give my stepmother, I would try to think of one little thing we had done together when I was small, she and I both thought baby animal figurines were cute, for example, and she had a lot she shared with me/let me "play" with so I sometimes would buy cards that reminded me of those/were a little childish. Otherwise I would get a card a teen might give, talking about not cleaning my room or something (something she and I might have argued about) or otherwise saying she had had trouble with me (rather than that I was having trouble relating to her). Since it was referencing something in the past, it kind of skated over the present situation.