I dislike Harper personally, its a profession not a name and always sounds masculine imho
both McKenna and McKinley are obviously surnames as is Monroe so sounds a bit silly (id avoid names starting Mc or Mac)
so I would say Kinsley Monroe is best
other suggestions:
Kennedy (I like this name and shortens to Kenna but may have historical implications lol)
Kelsi
Kacy
Kadey
Keeley
Kendal
Kaelyn
Kaley
Kassidy
Karenza