It may depend on the exact dates of your daughter's trip. MM entitles you to 30 days of downloads. The PP pictures will remain in your account for 45 days from the date they are taken. This gives you about 75 days from the beginning of the first trip until the end of the last trip to do downloads. If you buy the photo extension for the first trip, you could add 15 days and extend that time frame to 90 days.
So if your daughter's trip starts February 17, you would need to buy the photo extension for her trip in order for it to work (which is a great deal compared to buying a second MM, I think it is $20 or $30). You couldn't start downloading pictures until the very last day before the extended expiration date, April 17. From then, you have 30 days to take more pictures, make edits, and download them, giving you until May16 to finish downloading photos.
*****While this should work, please make sure that the dates are figured correctly*****