Vanillabean, it's hard to say. Your wife's situation sounds like where I was: been in the Citi family for a while; was at 4/6 when I applied for Citi Premier. Tbh after reading the blog post I thought I may not be approved. I took my chance and applied anyway and it worked out.

In these Covid times, banks have been re-evaluating who they are giving credit to, and how much. I don't know if anyone can tell you if you or your wife will be approved until you try.

Edited to add - I actually think your wife may be good. 3/6 means you cannot have more than 3 hard inquiries in the last 6 months. Your wife only has 3 inquiries.