I also have a preschooler and a toddler both highly extroverted and intense so yes, I can get run ragged and am still trying to figure out ways to keep them both happy since I am not able to have art supplies, small toys, puzzles, etc. where the younger sib can reach them. Both girls require and demand tons of adult interaction from me all day long and so days in the house can get long so we go to the library, storytimes, playplaces etc. My DD3.9 goes to preschool twice a week mostly just for a change of pace and to learn some social skills. I am not that concerned with teaching her directly at this age. We read a ton and talk a ton and if she has an interest, we pursue it. It is not easy with their activity levels and intensity levels, but I am assuming it will get better as they get older and can play on their own more etc.