Try treating her like a big girl. Take her into a shop like La Senza (they have fancy cotton panties) but of course, no thongs (they are going out anyway.) When she sees her older peers in there buying these fancy panties this should get her to wear them. Give it a try!
You may want to question your daughter and ask her why she doesn’t feel she wants to wear panties. Even small children can have problems in that area. A physical check-up by your doctor wouldn’t hurt.
tell her its either a nice beautiful pair of silk panties from her favorite designer, or a big old chunk of diapers.