Is it normal to have pushy friends?

Is it normal that I have a few friends who like to call me randomly and expect me to hang out with them at a moment's notice? One day last week my friend called trying to get me to hang out, but I was busy. When I told her I was busy with family stuff she got kind of huffy with me and I could even hear her husband griping about it in the background. I asked her what other days would be good for her to hang out and she told me what days she is off so I said "ok, I'll call you one of those days and see if you want to hang out then". It is easier for me to make plans a few days in advance.

Anyway, thinking it was no big deal, I went back to my business knowing I could call her on one of her off days. About five days later, I got an email from her asking me what I had going on in my life that would make me turn down having dinner with her and her husband?

Needless to say I was surprised to be hearing about this five days after she called me at an inconvenient time expecting me to drop everything while my family was getting together. I let her know I was surprised to still be hearing about this when I made it clear to her that I had plans that day.

Do others on this site have to deal with this type of thing from time to time? It seems pushy and disrespectful to me, and I wonder if others have experience with this kind of behavior and how to best handle it?