Wouldn't that border cannibalism?
It certainly would border it, but whether it really was, I suppose it would depend on what exactly those plant-looking parts actually are made of. A baby drinking the mother's milk isn't a cannibal, even though the milk is 100% animal product of the same species. There's an even more dramatic case among adults, which I will leave to your imagination, yet it doesn't make a human a cannibal for real, in pretty much anyone's opinion.
So, if those parts for her whatever race/species aren't anything fancy and traditionally have been eaten by others ritualistically or otherwise, perhaps even to grant the offspring some biological benefit, I wouldn't say it would be cannibalism.