[SARCASM MODE ON] I see that Wikipedia is spot on as ever on not copy-pasting poor tertiary source and always checking about them first[/OFF]
Seriously, this is why Wikipedia sucks. Their source is an eulogy that itself refers to a book which refers to the Menestrel de Reims...you got the point.
The scene which is described by happens after the Battle of Lincoln, and Louis needs finances to negociate his departure from England the best he can.
Phillippe Auguste is more than weary by the whole business and refuses to send Louis the revenues from Artois, probably in order to hasten the end of the expedition.
At no point it's question to make the grandson of the king of France hostage of Henry III in the middle of a war, doesn't name Louis at all (she say "I've many child from my lord", which could be any of the 3/4 childs she had), even less so to make it raised in England.
The idea itself is ludicrous, and would have she even attempted that, it wouldn't have ended well.
A good translation (rather than hostage) would be either "trust" or "pledge" their children to someone that will loan her the money that she'll be able to send to Louis.
Again, nowhere Henry is mentioned, and giving the dramatisation of the event by the author (which conveniently forgot about actual details we know by other sources) it's telling.
That's another case of Wikipedia being idiotic about copy-pasting sources from second hand.