Is it normal to of had sex with 4 boys if your only 15

tell your parents.

i mean clearly they're not keeping an eye on her if she has time to get laid that much.

Well when a relationship last a frekin week you will probably get laid often but hey what do I know I'm 3 years younger but se might be a whore

So? We develop sexually at that age. (No, I'm not a pedo)

Wanna know something I know a girl that is 13 who has slept with 11 guys. Feel better?

Your sister is what we call a hoe-bag.

You have to ask her why she's doing it?

Are you sure she wasn't emotionally abused or raped? Might she be looking to fill in an emotional void with "love" from boys? Was she ever an outcast looking to fit in? Has she typically ran with groups that stressed conformity? Did anyone ever have "the talk" with her? Was her father, well, a good father? Did you treat her well? Is she confident or have low self esteem? Was she ever in a serious relationship? How are her grades? Does she hangout more, or participate in organized activities?

There could be a lot of factors at play here. For 15, she could well be on the path to degrading her self-worth (not reputation).

What a parental fail! Tell your parents and make them straighten up a bit!

young people like to experiment :)

most will tell you it's much, but really, it just depends. Some are early bloomers, some late.
Some have one boyfriend, others will have casual sex with friends.

One's young only once, and tries many things, the hormones add to that, and once you got to a point were sex is enjoyable and the first time in the past, there's also less of a mental barrier to ending up in bed with someone.

Depending on when she started, that may be more normal than you'd think. 4 guys in, say, 12 month is just one every 3 month. Considering how fast relations with classmates and friends change at that age, thats very tame ;) Heck, i started having classic sex with 14 and with that same boyfriend and his best friend had a threesome at 15(it was kind of a mutual birthday gift kind of thing...young and stupid, as said...).

Just watch out a bit for her, and gently guide her in the right direction if she's in danger of getting a name for herself/becoming slutty.
Other than that, once that fire starts, little will stop it again, ESPECIALLY for young and stupid people like teenagers(no offense to the teenagers frequenting IIN, i am referring to the hormonal ravaging you are taking) ^_^