I am ambidextrous. I can write with both hands, and do most things with both hands, but in most daily activities, I seem to prefer left hand.
In my office, I moved the mouse pad to the left side. No one else could use that computer, so it always stayed that way. At home on the family computer, I used to move the mouse pad to the left side (and *forget* to return it), but my husband and right-handed kids would move it back to the right. After a while, I'd get lazy and just leave it on the right hand side and use it that way. I seemed to adapt very quickly and just stopped moving it.
Now, most of the time, I use the mac book air and notice that I use both hands to scroll and move the cursor. Same with texting.
Since your kids are so young, they will likely adapt even easier than I did as an adult (there were no computers when I was in elementary). Especially if they are reporting no problems, they will likely develop this dexterity without even thinking about it, and it can be a very advantageous skill in a mostly right-handed world!
J. F.