She seems into me but I can’t get anywhere

So I’ve(26M) been single for 3 years now for the most part by choice. Ended things with a manipulative ex girlfriend and about a year ago cut all ties with her completely and moved on. About 2 years ago I met a girl (22F) and we seemed to really hit it off. Her twin sister was dating a friend of mine and we ended up hanging out from time to time. Every time it always seemed like she had a thing for me and I definitely was attracted to her. But 2 years ago I just wasn’t ready to be in a relationship and wanted to have fun and stay single. I also was dealing with my ex trying to come back into my life at that point which didn’t help. Now that I’m well past that I’m feeling like I’d like to take a relationship seriously again and this girl keeps coming to mind whenever I think of what I want. We’ve hung out as friends a few times and she definitely sent some signals (arm touching, eye contact, some not so subtle questions about my ummm…size..lol and just overall flirtation) but when it comes to the “witching hour” when everyone is pairing off and what not she seems to get..awkward/shy. I’ve asked her out twice now. Both times she said yes but the first time we both had things come up that day and I asked her out to spend a day on my boat a few weekends ago, told her I had her on my mind and would love to see her and she liked my IG message (I don’t have her number yet) and responded “Yeah!” to coming out one day but then I didn’t hear back. It felt like I got curved but I’ve never had someone ecstatically say yea to an invite and then go ghost. Usually it’s “oh thanks! I don’t know what I’m doing so I’ll let you know.” and then ghosted. Which would make sense to me and I wouldn’t be asking Reddit.

From what shes told me she’s never been in a real relationship and I am a bit older and at a little different point in my life. She’s just finishing school and I’m 4 years into my career and kind of looking at what I want moving forward more seriously. So I’m not sure if it’s the age thing, she is lacking some confidence with this stuff cuz she’s never been in a relationship or if she’s just bored and likes my attention when it’s convenient. She seems like she would love to be with someone based on things she’s said in the past though.

I feel like maybe I need to just be even more upfront and tell her that I’m into her and would like to take her on a date or would that maybe too straight forward? We don’t talk all the time or anything. She’s not a big social media person and I like that about her but it means my opportunities to start conversations are limited. This is the first girl I’ve really felt something real for in years so I feel I need to pursue it but I’m not sure how straight forward I should be. Help me out people!!