MIL: Walking the fine line as a grandparent

Recently I've spent time with ILs and grandchildren.  First with Stena and her 2 little guys at their house while Freddie was out of town and then with my stepson, his wife and 4 children at our house.  Having been a mom for 26+ years and a grandma for many years less than that--and given that I'm still a mom to a teenager--I'm more a mom at heart than a grandma and I'm discovering that sometimes there is a fine line to walk...

Stena and Freddie are in the midst of toilet training their oldest son--and are doing a fine job.  He knows the ASL sign for "toilet" and uses it appropriately.  They also put him on the toilet when he wakes up--sometimes he does something and sometimes he just sits there until he signs "all done."  However, he's still just a little guy and sometimes forgets to sign when he needs to go so there are still wet diapers from time to time.  He's doing great though and I'm so happy for all of them.  However, that's not how I toilet trained my 4 sons...by the time they were 15 months old, I'd stand them on my feet in front of the toilet throughout the day.  Sometimes they'd go, but if they didn't, I'd take a bottle with warm water and give their--well, you know--a little squirt.  It worked like magic!  We'd still have wet diapers from time to time, but before naps, bed, and errand-running, I'd do my thing to ensure they had an empty bladder.  So, fast forward these many years.  Stena is busy with baby #2 and so I'm helping the big guy onto the toilet.  He's not doing anything on there and I spy a squirt bottle on a bathroom shelf.  I'm tempted to do my own thing to help him go, but I remind myself that I'm not his parent and I have no right to "do my own thing."  I am there to help and the best way I can help is to do what Stena does with her boys.  So I do just that...period.  No messed up little guy because grandma's doing something different, just consistency for him.  Makes for a happy little boy, a happy mom and yes, a happy grandma.

The next week is Thanksgiving and my husband's son and his family come for a long weekend.  There are 4 children in the family--ages almost 10 years to 3 weeks.  Since we moved south 3 years ago, their family has come to visit a 3 or 4 times a year...sometimes with their mom and dad, but sometimes we've taken the 3 older kids to give mom and dad a quiet couple of days together.  They are generally well-behaved and fun to have around.  Friday morning the 3 older kids were playing with our Matrylshka dolls (that my oldest son had brought back from his time in Russia) while their mom and I visited.  Suddenly child #3 threw one set of dolls across the living room (thank heavens for carpeting--they survived the fall!) and before I could decide on what to say, their mom was up and dealing with the situation.  She told him he could not touch the dolls for the rest of their stay.  He tested the limits with sitting close to his older siblings and "almost" touching the dolls with his toes.  Mom stayed focused on his behavior and when it was obvious he couldn't/wouldn't leave the dolls alone, she took him into another room.  The next morning I was in the kitchen when I heard the distinctive squeak that comes with taking one set of dolls apart.  Child #1 was standing beside me and child #2 was playing a game at the kitchen table.  That meant child #3 was in the living room playing with the dolls.  I went in and found him with all 3 sets of dolls completely taken apart.  I reminded him that the consequence for his throwing one of the dolls the day before was that he couldn't touch any of the dolls for the rest of the visit and told him to stand up and leave the dolls alone.  He told me that his mom had changed her mind and said it was ok for him to play with them.  Well, in this situation I decided it was my house and that my way of doing things was more important than the mom's.  I told him that while his mom might have changed her mind about the consequence, I had not.  He had been inappropriate with something that was precious to me and that he could not/would not touch the dolls for the rest of their visit.  He broke into tears and shouted, "I'm going to tell my mom you're being mean!"  I don't know what was said in that conversation with his mom, but he did not touch the dolls for the rest of the visit.


Did I do the right thing in that situation?  Since his mom had assigned the consequence, did she have the right to change her mind?  Is the mom/parent always right?  Did I overstep my bounds as the grandma?  Was I being mean to him?  Please share your thoughts.