my daughter went through the same thing last year. i just let her go without panties unless she was wearing a dress. then i would have her wear tights. but one day we were walking through tagret and she pointed to a panty display and asked me " what are those?" turns out she was asking about a thong display with all neon colors and she thought they were pretty. so i figured what the heck, small panties are better than no panties. and we got a pair. well, thats all she wears now. she told me she can hardly tell she is wearing them except for once in a while they ride up in the front. but it doesnt bother her.
i know its odd to be buying an 8 year old thongs, but its not like anyone is seeing them.
just giving my input.