Welcome! You will probably need to go with something at first because at her age she won't be able to hold it for long!
We use the washable peepads, you can get a frame type think at PetsMart for them, but I don't know how much it is.
We tried the litter, but our baby boy laid in it and tried to chew the pieces. We got worried he might try to swallow one and it get lodged somewhere, but that's just us!
Congrats on your new baby and be sure to post pictures!