I used to help my husband count the congo money and regularly went to the bank with it all by myself! I still type out the WT schedule for one of the brothers who can't use a computer well. Girls can do math, be trusted not to use congregation funds to buy shoes instead of taking them to the bank, and can also type even though they've been inactive non-attenders for a long time.
Girls are also great at scanning confidential elders textbooks and leaking them onto the internet before their official release, along with the BOE letter saying girls can't touch, look at or be within 50 paces of the elders book. (Slight exaggeration. How is YKnot nowadays, I wonder?)