Benadryl 30 min prior to infusion. Sort of when she gets there, as it will take FOREVER for her to do paperwork/set up. 25-50mg (1 or 2 tab) is typical.

I wouldn't risk the first infusion without pre-meds, especially since you are doing it at home. Most everyone does the first in the hospital, just in case there is a more severe reaction (extremely rare). The pre-meds should squelch the chances of that happening.

Good luck.