Is your schedule such she has lots of free time on her hands?
Would her dating 1 or 2 other people cut into your time as things stand now? Would you need to find some outside filler activity .
What is her vision of this ....once a week sleep over dates or is it more open ended and could be 50/50 time split and or joint housing.
The great thing for you is the opportunity to work this out before getting married.