Op, have a look at National Trust's website for "What's on for Families" in your area. There will be Easter egg hunts of course, but you might be able to find something like soft archery for the DC to do and some sites have adventure playgrounds, obviously your DD might have to sit those out, but at least the other DC can run about and let off steam.
What about a picnic by the beach or at a local nature reserve,
or visit to a Wildfowl and Wetlands reserve.
Sealife aquarium.
A ride on a steam railway, I have one local to me run by enthusiasts and there are often special days out during school holidays.
A visit to a smugglers museum, like the smugglers caves in Hastings for example, interesting and a bit spooky.
Horrible Histories Easter Escapades
Check your local library for Easter themed activities, lots are running free craft activities.
Some things your DD will just have to accept that she can't do and will have to sit out with a book or tablet, but the rest of the DC shouldn't miss out on everything just because one child is injured.