Middle names for Elizabeth and Beatrix

I am looking for some suggestions on middle names. We can’t seem to come up with anything we both like. I would like a middle name that’s at least two syllables, because the last name is only one (it’s Tree, by the way) and I don’t think a one syllable middle name flows very well. My boyfriend likes [name]Elizabeth[/name] [name]Iris[/name], but I’m not sold.

I’m not pregnant, just planning ahead of time. We would probably call [name]Elizabeth[/name] [name]Betty[/name] or [name]Beth[/name] as a nn.

Personally, I wouldn’t use [name]Iris[/name] if my last name was Tree- I’d actually shy away from all nature names (i.e. [name]River[/name], [name]Violet[/name], [name]Asher[/name], etc.). And I see in your signiture that you have [name]Olive[/name], a baby named [name]Olive[/name] Tree wouldn’t be ideal…
Here are some other ideas:

[name]Elizabeth[/name] [name]Claire[/name]
[name]Elizabeth[/name] [name]Clara[/name] (to get the 2 syllables)
[name]Elizabeth[/name] [name]Elise[/name]
[name]Elizabeth[/name] [name]Aldine[/name]
[name]Elizabeth[/name] [name]Monroe[/name]

[name]Beatrix[/name] [name]Merida[/name]
[name]Beatrix[/name] [name]Eloise[/name]
[name]Beatrix[/name] [name]Louise[/name]
[name]Beatrix[/name] [name]Charlotte[/name]
[name]Beatrix[/name] [name]Matilda[/name]

[name]Elizabeth[/name] [name]Daphne[/name]
[name]Elizabeth[/name] [name]Irene[/name]
[name]Elizabeth[/name] [name]Gaia[/name]
[name]Elizabeth[/name] [name]Nina[/name]
[name]Elizabeth[/name] [name]Zoe[/name]

[name]Beatrix[/name] [name]Joy[/name]
[name]Beatrix[/name] [name]Lucy[/name]
[name]Beatrix[/name] [name]Eva[/name]
[name]Beatrix[/name] [name]Blythe[/name]
[name]Beatrix[/name] [name]Emily[/name]