It all depends on what type of holiday the are looking for can you give us a clue and we might be able to help.

Well obviously a family holiday, some entertainment for the kids etc

Hi,me and my family went to lloret last May and had a great holiday,although my kids are older 13 and 15.
There was plenty to do,boat trips,ten pin bowling,two aqua parks,we went to marine land which was a aqua park,but it also had a fantastic dolphin and sealion show,it was a great day out,but catch the free bus from lloret bus station,don't do it with the reps,a lot more expensive!!
The beach in lloret isn't sand,it's more shingle,but very clean.
Good choice of restaurants,from spanish,chinese and of coarse english,also a burgerking,which was great for the kids.
Fenels is also nice,which is only a 15min walk away or a 5min bus ride.
I'm sure your sister and her family would enjoy lloret,there are ton's of shops and a big outdoor market once a week,if you wan't any more info i would be more than happy to help,luv,Maz,xxx.

I've been to both and got to say although estartit is nice Lloret is definately the place to go