the gemara asks on rava how a ktana can become pregnent.why cant we answer, that the question of rava goes like r.meir - she became pregnant before bagrus and that is the reason for her death? (chachomim= she cant become pregnant. r.meir= she can but it will kill her.)
menachem wieder, london, england
Rebbi Meir holds that there is no Kenas for a Ketanah. Consequently, if she became pregnant as a Ketanah (which would give her time to give birth before she reaches Bagrus), there would be no Kenas anyway. In addition, see the Rishonim who point out that the Gemara in Yevamos says that "Banim k'Simanim," so if she gave birth she would be considered to be a Na'arah, retroactively back to the time of conception, and thus she would be a Bogeres before the birth.
D. Zupnik