[my mostly serious tag]
Sadly, I doubt she will get any help, because that would require Riot employees to put on their big girl panties and admit there is a fucking problem. I've told them this on numerous documented occasions with my legit account.
As an adult, most of these low life retards amuse me, but It will be sad/funny when some kid ends up hurt and Riot game ends up in court claiming they had no idea.
As far as I know there are 3 ways this is occomplished:
ONE. Assistance of a Riot employee.
TWO. Dumb kiids/adults who are prone to the darker side psychology of group dynamics will send messages in game to people they don't know who are playing with the summoner they want to harrass, and tell them to throw the match for XYZ reason. (I've on various occasions gotten such messages, and if you don't know what's up, you're first inclination is to help.)
Does Riot have access to these private in game chat messages? Do they regularly review such messages which ask others to grief and throw matches? Who the F knows... but probably not. There is not much you can do here, given the low IQ of most summoners, but I guess you could try saying something beforehand, and hoping for the best.
THREE. Various methods/apps which I can't/won't share, which give even the dumbest of summoner, access to things like who is in queue for matches, and try to correlate what other summoner accounts they use. etc etc
Riot should be actively blocking such attempts, but like I said in number 1, often times a Riot employee is helping out. Not much you can do, even if the employee is caught, they laugh it off and claim it's just harmless prank, and there is apparently zero accountability for such things internally.
Changing her summoner name will offer little if any relief.
Anyway, sorry to be a total downer, but please update and let us know if your friend gets any help for her situation. I would love to be surprised. However, as usual, this will probably only get attention after it ends in tragedy for some poor kid.
Furthermore, it's impossible or impractical to block all the summoner names, as these trolls often have dozens of accounts, and if those accounts get blocked they recruit some other dumb ass. Case and point, I thought nothing of adding my harmless looking neighbor to my friends list, but sure enough the asshole ended up getting messaged and helping to grief my games. So basically the only solution is add no friends? No, the solution is to add privacy settings and block exploits, and for RIOT TO DO THEIR JOB AND INVESTIGATE SUCH CASES ACTIVELY by searching the private chat log of the summoners accused. That's something only Riot can do, and they would quickly find that those people are usually also active booster/cheaters.
