Hmm . . . tricky situation.
I think the safest bet is to generalise in the thank yous. I had several friends who specifically helped me with my book, but when it came time for thank yous in the acknowledgements, I knew if I singled them out I could hurt some of my other friends. So I did a generic friends and family statement, which was totally heart felt of course, but also didn't offend anyone (and made sure that those specific friends knew who they were by telling them in person).
You don't need to thank your mother specifically, but I think, in order to avoid further strife and just annoyingness, you're best to just say thanks to family and leave it at that.
But do keep the dedication as is. No one could begrudge you that privilege.