Woman (47F) that I (32F) like at work told me that texting isn’t her ‘style’

I have a massive crush on my colleague at work. In person, I feel like we have a strong connection - we talk, flirt and laugh a lot together. At work and when we go out with other colleagues, I catch her staring at me when I’m not looking and if we do make eye contact, we’ll lock eyes for 4-5 seconds. She also makes a big effort to be physically close to me in person. She’s also invited me on an overseas holiday with her (which I didn’t go on) and makes hints at going on a holiday with me in the future. I do feel as though my feelings are reciprocated. However, the one thing that makes me unsure is her texting habits. She’ll rarely respond to my texts - sometimes not even opening the messages at all. I’ve brought this up to her in the past, and she said that it’s ’not my style to text’. When we talk on the phone, we have good conversations. But she seems to not want to text me at all. Should I be concerned about this?