1.) Write check, give her check, she goes to her bank, deposit check, (trusts me), (2-3 days)
2.) Pay 20$ regardless of size to have money wired to her (close to instant)
3.) Get cash out and go and hand it to her. (Quick but inconvenient, she lives on the other side of town.)
4.) Pull out cash, drive to her bank, deposit money in her account. (same as 3, but less inconvenient, still a PITA)
5.) Money order, etc
6.) Have wells fargo 'Bill Pay' cut her a check and mail it automatically (takes 3-4 days, this last month I had it scheduled for the 25, which landed on a saturday, they said the check would arrive on the 5th! (plus then the time of the check clearing in her bank.)