הלכה על פסחים 216:1

However, most commentaries understand that the words “they too” (“af hen”) indicate the primary obligation applies to men (who are obligated in time-bound positive mitzvot) and that women are obligated in the mitzva secondarily because “they too participated in that miracle” (Tosafot Pesaḥim 108b and Megilla 4a, Rashba, Ritva, Ran, Me’iri, and others).

Women are obligated to perform all the mitzvot of the Seder night – retelling the Exodus from Egypt, eating matza and maror, drinking four cups of wine, and reciting Hallel – for they too participated in that miracle (Pesaḥim 108b; SA 472:14; MB 479:9; see earlier in this chapter, section 4). This is only yearly occasion when women are required to recite Hallel (Tosafot, Sukka 38a).¹According to Yeḥaveh Da’at 5:34, even women at home must recite Hallel with a berakha on Pesaḥ night before the start of the Seder, just like men customarily recite it in the synagogue, because it is recited in praise of the miracle. This is based on Sephardic custom, as mentioned in SA 487:4. However, according to Rema’s custom, it is not recited in the synagogue. Some say that even in Sephardic custom it should not be recited by an individual (Beit Yehuda). Accordingly, women who are at home should not say it either. Since this is a matter of uncertainty pertaining to a rabbinic enactment, halakhic practice follows the lenient opinion and women are exempt from the recitation of Hallel before the Seder night. See Mikra’ei Kodesh ch. 3 nn. 18-19, which states that many women did not know how to recite it so it is inconceivable that they would have been required to recite it while home alone.