Seeking advice 🙇🏼‍♀️

My sister is expecting in August.. almost a year after I had my little one. She through my baby shower for me last year but it was awful because my mom and her got into a huge fight. My boyfriend got drunk and I ended up having to carry all the gifts myself, and put away all the food because everyone just left me! Welll, anyway I always thought I'd be the one to throw her a shower when she did have kids. Over the holidays( thanksgiving, Christmas..) she visited and recently started dating someone new after a 2 year long divorce. She told me she did not plan on having kids for awhile but ended up falling pregnant. Unfortunately I can't afford to throw her a shower because we can't afford it,and she doesn't even want to travel the 8 hours since she's 5 months pregnant now. Her newly boyfriends mother decided to throw her a shower. Well I'm trying to make plans to go with my family down there and every time I ask her dates she tells me she's going to be so busy she won't have time to visit with us, that I should come a different weekend( meaning I'd miss her shower).. since I'm her sister I feel like I SHOULD be there but she's acting like she doesn't care? And maybe doesn't want me to be introduced to his family just yet? ..a side story: back track a few years back.. I surprise visited her for her bachelorette party and she wasn't even happy to see me at the door. She seemed offended by what I was wearing( I dressed in short dress, nylons and high heels while her friends were all like preppy dressed?)and I spent the night getting drunk with one of my friends instead. I was so hurt and felt like she didn't want me there. Anywhooo back to this.. I don't know what I should do. Should I still try to make the shower? Or just go when she actually wants me there? It's an 8 hour trip and my LO is nearly 8 months. I don't want to go if I'm not welcome.