I have a 15 month old daughter who is fussy all the time is ibuprofen good for fussy toddler?

Why is she fussy? Try to find out why she is fussy. Motrin may help with pain.
Depends. You can use it sometimes when she is not consolable but try to find out , why she is fussy , may be she is teething . We need to know if she has any other Sx . If Fussiness is with other symptoms , you may need to find out whether she has ear infection. I recommend seeing a Pediatrician.