How do I get Marie to talk to me again?

My social link with Marie (Aeon) is currently at Rank 4. I am in August 2nd and am on summer break. According to this link, Marie is available on Wed/Sat/Sun and all holiday days but not on rainy days. It also states that Rank 5 becomes available after July 24th. Since July 24th, there's only been one rain day, but she's never appeared outside the velvet room. If I go in the velvet room and speak to her, she says something along the lines that I (the protagonist) am busy right now and she doesn't want to talk to me.

What am I doing wrong? What should I do to get her to spend time with me again?

She will not talk to you until after Rise Kujikawa joins your party. Even the link you shared states that.