Several small doughs. If a woman made the minimum amount of dough, even if she plans on splitting it up, e.g., she is making several smaller challos, she still does hafrasha with a bracha according to most poskim (פתח"ת יו"ד סי' שכ"ו סק"ב, שו"ת שבט הלוי ח"ד סי' קמ"ה הערות שכ"ו ס"ב ).
For multiple people. However, if she divides the dough planning on sending challos to others, and she wants specific challos to go to specific people or she wants to send the doughs to different households where they will be baked, hafrasha is not done, as no one person is receiving the minimum amount of dough (שו"ע סי' שכ"ו ס"ב ).
Gan activity. Often, a morah bakes challos with her students, with each child assigned a specific piece of dough. Even if the morah bakes all the dough in her house, hafrasha is not done unless she leaves a portion large enough to independently require challah for herself.
Distributing after baking. If she is planning on distributing baked bread or cake rather than dough, the chiyuv hafrashas challah remains in force (ט"ז שם סק"ב וש"ך סק" ה ).
Sending challos to neighbors. If a woman bakes several challos and subsequently sends them to various neighbors or to her adult children, she must do hafrasha since she distributed challos rather than dough. Some say not to make a bracha (שו"ת ארץ צבי סי' מ"ט, שו"ת מנח"י ח"י סי' ק"ב ) unless she keeps a minimum shiur [even by Rav Chaim Na’eh’s measurement] for herself; others say she may make a bracha (מו"ר בעל שבט הקהתי ).
Saving for next week. If she makes the minimum shiur of dough but is only baking some now and is freezing the rest to be made later, the poskim debate what to do (לחם חמודות הל' חלה אות כ'). Some say she should separate challah without a bracha (מו"ר בלקט העומר פ"ז ס"ג סוף הערה ט'); others hold she may make a bracha (קובץ מבית לוי ח"ה עמ' ל"ו עפ"י שבט הלוי הנ"ל ).
