My dd was a super light sleeper. There could not have been any alarm use in our house without waking her. Some babies will sleep through an alarm or can be easily settled after, and some babies can't. Honestly there isn't much you can do to change it. At 7 yo my dd can now sleep through that type of disturbance but that is a normal shift that happens for children as they transition from infancy to childhood. Babies are supposed to be light sleepers. If I were you I would start by testing it out on the weekend, that way if your baby decides she's up for the day after the alarm goes off, you and dh can trade off care to give each other naps to make up for the lost sleep of an early morning waking. If it doesn't work you could sleep together on the weekend and dh could continue to sleep elsewhere on work nights. I will say that if I could have done it all over I would have gotten a full size bed for dd's room from the get go. That way she and I could have slept there together without depriving dh of the comfort of a real bed. Also it would allow me to nurse her down in a bed, but then slip away for some adult time in our room with dh, and then go back to sleep with her when she woke in the middle of the night.
Jennifer, mama to darling dancing Juliette, and sweet baby Jameson