Know-How Exchange : Taglines/Names

Realtors are in business to sell them selves.

If you are looking to be in real estate for the long-term. I would stick with using your own names instead of Barbie and Ken. It will eliminate confusion in the future and brand you for the expertise you provide.

If I were considering a realtor to help service my needs I would expect to use someone who would be taken seriously.

I think Crystal & possibly your fiancee's... is a fine name coupled with a good tagline for each of you.

Married To Real Estate
Two Heads Real Estate
The Real Estate Couple

His and Hers Real Estate
Real Estate for Partners

Keller and Williams is already an established real estate firm and you could get away with being a little more playful but not silly. You want to target everyone in this market so instead of using a playful name or tagline, you could do it in your print listings and advertisements to show that you are a serious and respectable team but you are also energetic, young and fun.

You could use your first names or your fiancee's last name (Which will soon be yours, since it may be difficult to incorporate both of your last names.) For example:
.... and Company
.... and Co.
.... & Co.
.... Team
.... Power House
You could also use .... Duo with the tagline you suggested or something simmilar using Dynamic.

A tagling that I like is "Our Family Helping Yours" or you could play off of your name Crystal and do something like "Fiancee's Name" & "Your Name" with a tag like "The Clear Choice for Buyers & Sellers".

Good Luck!