Intuitive Bid

My girlfriend Alice and I arrived back in Chicago yesterday morning exhausted from a long weekend of partying in New Orleans. It was a great time, though the partying went better than the bridge for the most part...I'll try to post a few hands in the next few days. I was planning an afternoon sleeping my way out of the daze and then a relaxing dinner/cards night with friends including Dan Wilderman, who is visiting from New York. The sleeping part of that plan was put aside when I heard from Dan that he and Kenny were planning on playing the afternoon game at the local club--Alice and I decided to join in the fun and soon found ourselves sitting North-South at table 3!

Alice has still played less than 10 rounds of duplicate and our convention card includes nothing more than 16-18 notrumps, Stayman, and forcing double-raises. You might imagine my trepidation, then, when I held this hand in 3rd seat with none vul and faced a challenging auction:
AJ9x
Jx
K9
KJ98x
The opponents were silent throughout. I opened 1 Club and Alice responded 2 Diamonds. We had not discussed passed hand jump shifts so I tried to imagine what she had--I came up with a maximum pass with an excellent diamond suit. Going on this assumption, I had a few options--I could pass if I thought we were high enough, I could raise diamonds, or I could mention my spades. I figured that my hand was minimum, but the king of diamonds was likely to be a big card, so I wanted to keep bidding and decided to bid 2 Spades on the way. Alice bid a prompt 4 Spades and again I was concerned, mostly because I thought that I had overbid. LHO led a low heart and Alice produced this fine dummy:
KQT
xx
AJTxxx
Qx
I was delighted to be in the only game contract with a legitimate chance! Normal splits led to making 4--the only +420 in our direction. I was proud of Alice's evaluation of her cards on this one--she could tell that they were all pulling full weight. Well done partner!