Me and my husband are in the same situation and you may be able to benefit from our experience (we also use an immigration lawyer) Husband has green card (LPR)- I am Cdn citizen. We married 2 years ago. At that time he had green card for 3 years. In order to live in the US as spouse of LPR, you file certain docs and have a 5-6 year waiting period. As a spouse of a citizen, the wait is approx 4 months. In many cases you are better to first naturalize, then file to bring the spouse to the US. You can begin the naturalization process 90 days prior to the 5th anniversary of your green card. The time it takes to naturalize varies from state to state. In our state it takes about a year. So for us, it has taken over 2 years to start the naturalization and another 1.5 years to get the naturalization and then apply for the K3 (spouse visa). That is a total of about 4 years (but still better than the 5-6 years for filing as spouse of LPR). After the K3 there is still a number of additional filings but at least spouse can live in US,
I know this sounds pretty glum. The CDN spouse has other options on her own - ie - business, NAFTA or student visas to stay in the US which you can also look into.
One thing our lawyer advised was that it may be best to not start any paperwork on Cdn spouse until after naturalization. The reson for this is when visiting the US, the spouse needs to demonstrate that she still lives in Canada and will be returning. Once the paperwork starts, the name gets in the "system" and the agents will know that it is the intent to eventually immigrate to the US making it more difficult to prove the intent to return back to Canada. Hope this helps and let me know if you need anymore detail. I can point you to various websites etc.