Cradle Catholic here. Raised nearly all of my life in āUtah north,ā otherwise known as Idaho. We need a bumper sticker: āIdaho, the lighter side of Mormons.ā
I agree with nearly every single thing RebeccaJ said with one difference. I attended Sacrament Meeting with my LDS friends and they came to Mass with me. My dadās rule was if I went with them, they had to come with meā¦and on the same Sunday. That deterred any but the truest friends. (They all came to my wedding eventually, too. And I have waited in many an LDS temple waiting room.)
Like any other part of our childrenās lives, we as parents need to know the parents. If a mom of one of your childrenās friends has any āStepford wifeā qualitiesā¦run far and fast. Nowhere in LDS theology does it say, āWomen will be mindless drudges.ā Get used to the title of āBrother Smith, Sister Smith.ā It is weird at first. They will look at your children strangely in the beginning with the āMr., Mrs.ā address, but they get over it eventually.
If you are the type to welcome debate when they knock on the door, do so. If they donāt want to listen too, say something. Call their bishop if you have to. Yes, yes, yes, keep the sacramentals up at home, but donāt force the kids to wear them if they donāt want to. They WILL get hassled over them. Be aware that ward boundaries are drawn along school district boundaries. That was a big shocker to my parents.
Open discussion is so important. Learn about LDS beliefs, talk to your kids about them side by side with Catholic beliefs. A book I recommend is āA Tale of Two Cities: Catholics and Mormonsā by Fr. William Taylor. He does just that in his book, presents the basic theologies side by side. But mostly, let your kids be kids and make friends. My friends from Utah say that some of their fondest memories are meeting their first Catholic and finding out the whole world wasnāt LDS. It made them want to learn more.
Looking back on my upbringing I find it is the truly devout, practicing LDS who have remained my life-long friends. It was the half-active, overly zealous Mormons who tried to tear me from the Catholic Faith. It almost seemed that if they could convince me that the Mormon beliefs were right, that they could convince themselves. They are either no longer LDS or no longer my friendsā¦or both.