They do Ear Planes for children as well, slightly smaller ones.
I sympathise greatly with this, DD (now 11) gets terrible pain in descent and I have tried everything to ease it. (I am not a horrid mum - we lived in Australia for two years, planes were part of our lives!) here are the results of our attempts.
Calpol and nurofen given an hour before landing - helped a bit
Compulsively chewing (gum or chewy sweets like starburst) - helps a bit
Sucking a lolly or sweet - didn't help
Sipping water - helps a bit, a bit more if drunk through a straw
Normal squishy ear plugs inserted an hour before descent starts - helps in combination with other things
Blowing up a balloon - failed miserably! Although did make her laugh when it burst
Ear planes - DD didn't like them at all
Over ear headphones - sometimes helped a bit
Regularly blowing nose - helped
Hot towels - this was the most helpful and only discovered on our last flight! I took some of those hand warmers and a couple of damp flannels in a bag, snapped the hand warmers, wrapped the damp flannels around them and placed against her ears.
Having said all of this DD now won't countenance a holiday anywhere that involves flight. She tells me that the large liners A380s and 777s are worse than the tiny easyjet types - I am guessing it is to do with the height they travel.
We are now back in the UK - so continental Europe holidays for us!