Definitely not wrong! BUT...again like said before, you can't change people. What you can do though is sit down and try to come to an agreement. Remember, you are having her watch your child, payment free (I assume), and though that gives her absolutely no right to interfere in the way she did, in her mind, it might be an even exchange or she might see it as, you need the help and just don't know it. If she wants to do things, maybe make a clear list of what she is allowed to do...?
My MIL and I will probably be battling our differences until the day we die, we love each other, but we don't like each other very much, at least not always!
Best thing I can say is, call her, email her and arrange a time to sit down with her. Let her know that you need to clear the air and I would do it just you and her, without your husband. Clearly and calmly state where you stand on things and why and thank her for her help, her time etc, but remind her that it's your home, your child, and ultimately your decision on how things are done and that you need her to respect that for everyone's sake, if she can't...well...let it go, you've said what you need to and in my experience....grandma's don't like being kept out their grandchildren's lives, so she'll come around! ( I know I sound harsh...but it's really tough love) relationships with family shouldn't come at the expense of your comfort and happiness.)