When you run out of space, you've reached the limit and it's time to stop. As long as you love them and enjoy looking at them don't worry what others think. If relatives think your house is too "quilty", perhaps they should keep it to themselves. If she's comfortable enough to make these comments about something that's obviously dear to you, then perhaps you should be just as candid and tell her you're not interested in hearing her negative opinions about your decor.
Kind of snarky, but sounds like she could use a lesson in sensitivity.