I have problem understanding the following scene from a manga (Yotsuba&! vol. 1 pg. 196):
Person A: Oh yeah, what about Yotsubas mother?
Person B: ああ こいつ ひろわれっ子なんで かーちゃんいないんだ
(I put spaces where line breaks are in the manga).
I understand parts of that sentence but can't find what the phrase in the middle of it means ("ひろわれっ子なんで"). As the character for child is the only kanji I have trouble even knowing how many words are in there, and dictionaries aren't of much help. I found a translation of the manga online and they claim it means
Oh, she was an abandoned child so she doesn't have a mom
but when I tried searching "abandon child", It appears the verb "捨てる" is used (like for example here: 彼女は自分の子供たちを捨てた). Could you help me understand what exactly is said in there?