I have a 7month old female spider bp.
I feed her a rat pup once every 7 days, approx 10-15% of her body weight. Is once every 7days enough, or at her age should I be feeding her more frequently?

A less important question, I am making an online order and get free shipping if I spend more than 200$. I don't know what else to get besides 2 identical exo-terra hides. What size would be appropriate for a full grown female bp?

http://www.exo-terra.com/en/products/reptile_cave.php

Those are the ones I am looking at. I am deciding between the large (9'' x 11'' by 2 1/2'' tall) or the xlarge (11'' x 11'' by 4 1/2'' tall) and was wondering which size would be more appropriate for a full grown female bp

Thanks