This is really a follow up to a comment to the previous post which questioned my use of the word "obligated" with respect to women reciting birchas hatorah. Shouldn't I rather have said that they are "entitled" to say the bracha?
The answer I think depends on why women can/should say birchas hatorah in the first place. Although women are entitled to perform mitzvos aseh she'hazman gerama like sitting in sukkah, hearing shofar, etc., the Beis Yosef paskens that they are not permitted to recite a bracha because they have no obligation to fulfill these mitzvos (the Rama disagrees). Why then does the Beis Yosef pasken (O.C. 47:14) that women may/should recite birchas hatorah when they have no obligation to learn? A number of theories have been suggested:
1) Women are obligated to learn the halachos which apply to them (Maharil, Agur, B"Y).
2) Women are obligated to recite pesukim as part of davening (ibid.)
3) Birchas hatorah is on the cheftza shel Torah, the subject matter, irrespective of whether there is a chovas hagavra to study (Brisker Rav, see this post)
4) Women must see to it that their husbands and children learn, which is part of being "oseik" in Torah (Chasan Sofer)
5) Birchas hatorah is a birchas hane'henin which a women must recite over the pleasure she gets in learning even if she is not obligated to study (R"Y Engel, Lekach Tov #11).
I'm not going to debate the merits of any one of these sevaros now. Our focus is this: is the Shulchan Aruch which prohibits brachos on other mitzvos she'hazman gerama simply allowing a bracha over limud haTorah, or obligating a bracha over limud haTorah? It seems to me that according to any of the reasons given a women in in fact obligated to recite birchas hatorah. Unlike zman gerama mitzvos where women have no obligation and hence may not recite a bracha, in some way women are included in the obligation of engaging in minimal Torah study, encouraging Torah study, they partake of the enjoyment of Torah study, or simply texts of Torah demand a bracha before being studied irrespective of whether the learner is obligated to study them or not -- therefore a bracha must be recited. It is that very distinction between obligation and lack of obligation which separates birchas hatorah from all other brachos on zman gerama mitzvos.
The GR"A comments on this din that women may recite birchas hatorah just as they may recite brachos on any other mitzvas aseh she'hazman gerama. The GR"A is clearly not explaining the Beis Yosef's position, because the Beis Yosef holds that women may never recite a bracha on zman gerama mitzvos. Rather, the GR"A is offering his own justification for the bracha. According to this approach, birchas hatorah, like other brachos over zman gerama mitzvos, would be optional, not obligatory.
Nafka minah: Can women be motzi men in birchas hatorah? Certainly according to some of the reasons used to explain the Beis Yosef there is room to argue that men and women have parallel chiyuvim to recite the bracha (though the parallel may not be exact according to all the reasons). However, according to the view of the GR"A, hands down there is no comparison between the option to recite the bracha and the obligation to recite the bracha and women may not be motzi men.
If you pull an all nighter Shavuos, can you wake your wife up to recite birchas hatorah for you because there is a safeik whether to recite a new bracha when you are up all night? No, because it would be rude and inconsiderate to wake you wife at 4:30 AM for this reason. But lets say she is up anyway... maybe you could argue sfeik sfeika: safeik whether you wife can be motzi you, and even if she can't, safeik whether you are obligated to make a new birchas hatorah in the first place.
While on the topic, an interesting mareh makom. R' Chaim Kanievsky writes (and I have not seen it inside, only quoted) in his "Sefer haZikaron" that women need not be careful regarding those items poskim mention are "kashe l'shikcha", which cause forgetfulness, because they have no obligation to study Torah. The Halichos Beisa (ch 28 footnote 14) argues. Even sans a formal chiyuv of talmud torah, women are obligated to know and study practical halacha (reason #2 above). Hence, they too must be mindful (excuse the irony here) of anything that would cause forgetfulness.