lol boosting 'crackdown'?

trying to duo with an IRL friend. over the last month i bought 2 accounts and then boosted on 2 accounts. We had a session where we went on a huge winstreak (18-2 or something) and she got banned for 3 days and a huge rank revert (1 game off emerald down to g1). this was mostly while i was on another persons account.

some of these games she played on my pc at my house instead of her own.

does anyone have any guidelines on how to do this? should we simply not duo? should she only duo w/ me on an account that is mine? or literally she needs an alt to be safe? any suggestions?