A sole proprietor indicates they are a schedule C.  Are you sure about that?

so she has a designated office space that she only uses for rental property work?

I only have one of these, he's got multiple of rentals and an apartment building. 

I use a dummy Sch C to create the 8829, then print it out and use the dollar amount on Sch E in Other Expenses, I keep the printout in his file and delete the dummy Sch C.

Theres no way to link an 8829 direct to Sch E.