Best friend issues (help)

I have these two really close friends of mine and we all used to hang out together all the time. One is my best girl friend and the other is my best guy friend. I’m gonna use Tony as the guy names substitute and Rachel instead of her real name. So me and Tony would always ask on a group chat with us three when to hang out. Rachel would never answer or would always say she couldn’t come or said she was going through shit and she didn’t want to come. Us three didn’t hang out for a while and out of the blue one day, Rachel texts us and asks if we wanna come-over and swim. Tony and I say yes and head over to her place. We get there and we r all having a great time like we used to. Tony asks why Rachel wouldn’t answer our texts or come over. She simply just said that she was having fam issues. We believed her and after a week, I asked if we could all hang out again at my house. She never responded but Tony came over. Me and Tony we’re getting annoyed and hadn’t heard from her in months and we’d always invite her over but she would never respond. So it ended up just being Tony and I most of the summer. It was Tony’s birthday a month ago and he invited me and Rachel to come over and celebrate with him. I said of course but Rachel never responded until the night before his party simply saying she couldn’t come. He asked why and she didn’t respond. When I went over to his house, it was just me and him again. He felt so sad that she wouldn’t even come over for his birthday but when she asked us to come over, we were always there.

Honestly, she’s just being a bitch but I needed somewhere to vent other then telling Tony and making him feel worse. Any suggestions on how I can tell her to get her shit together? I know she isn’t actually going through stuff cause when I’d text her separately, all of it sounded too fake and made up. I’m just so tired of her blowing us off. Rachel is always talking about how we are her best friends and we are soo close and all this crap about friends for life when she can’t even pick up her damn phone and get off her ass to show up once in a while.

Comment or vent if this ever happens to you! Plz help me figure out a nice but serious way to tell her to get her shit together!!