Hi P.,
I'm not a Grandma but plenty old enough to be :) I homeschool my girls, 14 and 17, and have since the beginning. Our motives for homeschooling were specific but we had no idea that we would have so many benefits as our lives changed. My husband is self employed. We took in both my parents several years ago and added a lot of stress, and joy, in our lives and there has been trauma in our lives in other areas. Homeschooling worked through it all and probably worked better because of the situations we were dealing with.
I applaud your diving in! There are so, so many curriculum that you can find exactly what you need for both of them. Some are very hands-on while some almost do the work for you. You determine exactly what they need AND you need, and then search it out. Feel free to get back to me if you would like specific direction with specific needs. There are also sooooo many homeschool groups that give support. I know the one in my area has a bookswap once a year so you can end up schooling for almost no cost. It also gives you ideas on which ways to go with each child. I personally teach to my child's interest. It makes it so much more pleasant when the child is studying exactly what they want to learn. It will fit somewhere in the states requirements of studies.
Homeschooling also does not take as much time as a normal school day. If you factored in the one on one time kids get in public school it would be shameful. Most homeschool families spend mornings schooling and the rest of the day is theirs.
This is a simple task, albeit a critical one. I asked a very dear friend of mine one time if he homeschooled. He said, "Doesn't every parent?" meaning by the time they are coached and helped at home with their homework, the time spent there could probably have schooled them completely.....
God bless!
M.
P.S. I have seen absolutely no pitfalls from homeschooling and you'll hear that from most homeschooling parents. As a grandparent you have a lot going for you from the beginning!