Mrrzy,

I am a Canadian, I have many relatives in the U.S. who we visit frequently. Both my sister and I are separated with Children. We have both made several trips into the U.S. with our children over the years. Neither one of us has ever had any difficulty going or coming. Only once was I asked if the little ones in the back were my children to which I replied yes, I was then asked where their mother was to which I replied "working", he then asked if she knew they were with me to which I replied yes and he waved us through. But this was only once and I'm sure that over the years we have probably crossed 30-40 times between us.

I wouldn't worry if I were you.