Hi BikerHen,
sorry you can't make the trip.

I think perhaps you mean your sisters are going boating on the River Avon? Maybe even taking in Stratford-upon-Avon to go to Shakespear's birthplace?

Do they enjoy cycling too? If so they might want to see where they can hire bikes for a day? Sadly cycling is not permitted on most riverside footpaths, unlike canal towpaths. However, the river Avon's valley includes some quiet country roads which are ideal for a leisurely cycle ride. You can cycle from Evesham to Tewkesbury. There's a nearby railway station at Ashchurch, where a train will take you back to Evesham (change at Worcester). There's a pub called The Fleet Inn, at Twyning near Tewkesbury, which is recommended as a good lunch stop for the hungry cyclist. (So I hear, not having been there myself.)

Every English town has a bike shop somewhere so your sisters should be able to find you something you'll like. Also, every English town has a tourist information centre where they will be able to get advice about where to ride, hire bikes, etc.

Hope they have a wonderful holiday.
Mhara