Well not sure how old your granddaughter is but there is Mulligans is Murrieta. Then there is bowling in Murrieta also.
In temecula there is a great place for all ages called
Painted Earth
27507 Ynez Rd
Temecula, CA 92591
(951) 676-2447
This is a great place to go and paint your own little ceramics! I have taken all age kids there!
There is also Chuck Cheese, in murrieta! Which I dont care

for but the kids LOVE it!!
There are also some great parks all over.
There is also a great little water park for the little ones at:
Diamond Valley Aquatic Center
The new Aquatic Center is open daily and houses a play gym and water slide for all your water fun.
Call (951) 929-0047 for location, pool times and fee information.
It is $6 per person and I believe it is open from 10-6 and you can stay all day for that price.They have fishing and boat rentals as well.
I hope you find some of this interesting
Have a great time and let us know if you did any of these things,would love to hear if you had fun!