You don't know what compelled you to do it, but you decided to explain what the both of you are gonna do. Of course, the shrinking part is hard to explain since whatever way you'll phrase it will sound insane.

So, instead you demonstrate it by shrinking in front of her using the Raygun in hand. Shocking Barbara, as she gasped in amazement. 

She steps a bit Infront of you, picking you up carefully using her fingers and placing you on the palm of her hand, still amazed at this almost unbelievable events.

For a moment, the both of you didn't say anything, but know that with you shrunken it opens up to a lot of fantasy fulfillment. 

The question now is, how will she do it?