Hi, Tim,
Hilary is great! Thank you for recognizing her awesomeness.
I'm not sure if she has seen this yet, or perhaps answered your question privately, but I'm going to answer here just in case she has been busy with life or someone else may need the info as well.
On your own profile, go to the Edit tab. Along the left side, look for "Spouses:". There will be a small link there to add a spouse.
Hope that helps and welcome to WikiTree!