You are your child's guardian, their advocate. It is your duty to do the best by them, always. It doesn't change for us at Christmas or when family are visiting.
Often Christmas can be difficult when families come together. Often when different values come together, different life experiences. Having family visit or travelling can often be overwhelming for children.
Consistency is really important. Otis has been a little more distracted lately and harder to settle at bedtime. I believe this is from a change in diet (more treats), later bedtimes and the excitement of Christmas.
We no longer discuss Montessori or our parenting philosophy at length with family. Although when Caspar was little it was a hot topic. Everything from crying it out, extended breastfeeding to our choice of toys and school.
What has changed is that our family over years have been able to observe us as parents, our philosophies in practice, Montessori in action. Looking back I think this is key. To convince family about the benefits of Montessori there were no discussions or words that could change their minds but it was the actions of our children, the outcome, the tangible. I could talk all day about the benefits of Otis using real glassware or what Maria Montessori said however it's not until they see a rambunctious toddler slow down and carefully (in silence with great concentration) pour a glass of water (and then wipe up the spills) that they see the benefit.
Before Christmas or birthdays I think it's great to have a conversation with family about gifts. If there are toys you don't want in your home this needs to be made clear. However it is important that we lead by example. If our homes are full of commercial characters it's likely family and friends will feel comfortable to give these as gifts. If our homes have well considered toys carefully selected for their natural/educational/whatever you feel is important qualities, then family are more likely to ask or select similar toys.
What to do with unwanted gifts? Often it's my husband who has chooses the most inappropriate gifts for our children and that a whole different discussion! I think it's most important to demonstrate grace and thank the gift giver. We have always allowed our children to play with the gifts and for those that have really rubbed me the wrong way I have put them up (out of sight) when the children lose interest in the toy, this can take anywhere from hours to days. Then in time, before the next Christmas or birthday, I have given more suitable gift ideas to the gift giver. If the toy was really offensive I would probably remove it from the children as soon as we part from the gift giver. It's more difficult if you believe the gift giver will return and want to see the toys played with.
Grandparents in particular love to spoil children. In our family this is often with treats but also to help and assist the children as quickly as possible. This year we have been fortunate to have Grandparents stay for extended periods. While we allow them to spoil the children as much as possible (it's their right - no?) I have many times (it's easier on my side of the family) stepped in and said "please don't help him he can do it himself" or make it clear what the children are capable of "Otis will like to select his own clothing, he can get dressed himself but he might need help if his arms get stuck and please don't worry if he puts things on the wrong way", "The children can get their own glasses of water but they may come to you for help if the water dispenser is empty". This of course is much easier, it's easier to enforce when it's in our home.
Most of all I think that even the most stubborn family will come to learn about Montessori over time, with our patience.