I love your daughter’s name! 
[name]Stella[/name]: I think [name]Stella[/name] is a very pretty name, and I think it’s great with [name]Hazel[/name] and your last name. 
[name]Harlow[/name]: I can see the appeal of [name]Harlow[/name], but its style seems really different to me from [name]Hazel[/name]'s, and I personally like the names that don’t begin with H better with [name]Hazel[/name].
[name]Harper[/name]: See [name]Harlow[/name].
[name]Violet[/name]: I love [name]Violet[/name] so much, but there’s a color theme with [name]Hazel[/name] and [name]Violet[/name], so I like [name]Stella[/name] and [name]Hazel[/name] more.
[name]Ruby[/name]: I love [name]Ruby[/name], too, but because [name]Ruby[/name] and [name]Kennedy[/name] have the same ending sound, [name]Stella[/name] is still my favorite with [name]Hazel[/name].
[name]Pearl[/name]: I love [name]Pearl[/name]. [name]Even[/name] though it’s also a color, I really like it with [name]Hazel[/name], and I think it sounds great with [name]Kennedy[/name]. (I love your last name!)
[name]Olive[/name]: I love it, but because [name]Olive[/name] and [name]Hazel[/name] are two shades of green, I still love [name]Stella[/name] more with [name]Hazel[/name].
[name]Lulu[/name]: I think it’s adorable, but I guess I think of [name]Lulu[/name] as a nickname for [name]Louisa[/name], [name]Louise[/name], and [name]Eloise[/name], all of which I think sound great with [name]Hazel[/name] and your last name.
[name]Poppy[/name]: See [name]Ruby[/name].
[name]Lucy[/name]: See [name]Ruby[/name].
[name]Iris[/name]: I love it! With [name]Hazel[/name], though, I think of a hazel-colored [name]Iris[/name] of the eye.
[name]Ivy[/name]: I love it, but I love [name]Stella[/name] more with [name]Hazel[/name], because [name]Ivy[/name] has [name]Kennedy[/name]'s ending sound, and [name]Ivy[/name] and [name]Hazel[/name] are two shades of green. (For some reason, I don’t notice the color theme with [name]Ivy[/name] as much as I do the other names, though.)
I love the names on your list, and love [name]Stella[/name] the most with [name]Hazel[/name] and [name]Kennedy[/name]. I love [name]Stella[/name] [name]Violet[/name] and [name]Stella[/name] [name]Pearl[/name].
(After [name]Stella[/name], I love [name]Pearl[/name] the most with [name]Hazel[/name] and [name]Kennedy[/name].)
Good luck! 