During the conversation if she says she has done something adventurous or spontaneous you could say something like “cool, I like my girls to be adventurous”.

Becareful with how you deliver this as it could have a genuine meaning as you like someone who enjoys life and pushes the limits where you can follow Carmo trail
or
it could have a sexually connotation as in you like her to get a bit 'freaky' which may get you a evil look and shot down quickly.

If you can pull the second one off you'll become a legend

I think the issue here is more about commitment and consistency. Just coming right out and asking if she is adventurous and spontaneous is not nearly as effective as incorporating it into some sort of routine. Get her to commit to being those things and it will work much better. Look at the Maury povich line…granted this is old and overused but you can see how it works. Also swingcat uses this stuff a lot with great success. During the conversation if she says she has done something adventurous or spontaneous you could say something like “cool, I like my girls to be adventurous”. Now what you have done is grounded that belief in her. So later on you can be like “wait I thought you were adventurous”. Or conversely if she demonstrates behavior that is not adventurous or spontaneous you could be like “that is weak, I like my girls to be spontaneous” and she will feel compelled to seek validation by showing you that she is in fact spontaneous. Just keep trying and see what works