Has higher than normal expectations; has a greater requirement for affection or attention; has more needs and/or demands and therefore more difficult or challenging.
Doesn't equate to money or material possessions alone but may be needy in emotional attention and affection;picky, bratty, likes things her way, takes pride in her appearance, finicky. Usually very well put together and usually independent therefore requiring a lot out of aman to keep up with her.
"If you have to reassure her through texts email or calls that you're lucky to have her, sheks so pretty, etc...- she's a high maintenance woman"
"If you have to put effort into wooing her as a true gentleman should, be lucky that you've snagged yourself a hot attractive high maintenance woman"