What are some kid friendly crafts?  

make a picture frame out of popsicle sticks for mothers day (grandma will love it) you can put a magnet on the back to put it on the fridge. what about making some salt dough to make some ornaments? there are tons of great (and free!) sites on the internet for kids crafts too!

Teach them to play go fish. My kids do puzzles together, board games, get some seeds and dirt and start an indoor garden.

We collect a lot of shells on the beach during the summer (and spring, fall & winter)and during the winter, my sons paint the shells. My youngest painted a lot of sunrises over the ocean- one of the shops I sold my jewelry in saw his shells and also put them in their gift shop...he sold a little more than a dozen shells last summer .
It's a fun idea, keeps the boys busy when the weather is too rough for them to be outside and they make great little decorations.
Hope your little ones feel better soon!