Hi Alexandra,
Thanks for stopping by with your question. We are always eager to help guests plan so that your vacation can be as magical as possible! I have traveled many a time with toddlers and preschoolers and there are still lots of fun things to do for them at Epcot.
First of all, my son absolutely loved doing the
Kidcot Fun Stops around World Showcase. This is a great way for them to interact with some cast members from the different countries while doing a small craft. As you make your way around World Showcase, be sure to ask where the Kidcot Fun Stop activity area is. It is complimentary and could offer something to do while the older sister and a grown up possibly do an attraction that isn't possible for the younger one.
Next, is the
Epcot Character Spot. This one-stop character location offers the opportunity to meet several characters and get autographs. It is located near Innoventions West and also not to far from The Land Pavilion. While big sister goes on Soarin', little sis could meet some fun pals. Also, in The Land is the
Living with the Land attraction. Again, this happens to be one of my kids' favorites. Even my older ones want to ride this over and over and they always seem to walk away having learned or seen something new each time.
My last suggestion is
Journey into Imagination with Figment. This pavilion adjacent to The Land has a cute attraction/ride and then offers some unique hands-on fun for the tiniest of tots at the end. We've spent hours in this area.
So, go explore and have fun.
~Allison L