When girl deliberately not read your texts, thoughts?

I feel like a lot of context is needed.

So there's this very beautiful girl at work who wasn't very happy about working here. Stars aligned and I got to have a chat with her a couple of times, she told me that she was going to quit once she finds another job and it had become our secret talk for awhile. Sometimes I would go into her department and give her treats like a brownie or a chocolate, and she would flirt when she sees me like tilting her head to the side, smile and wave at me. From what I feel, there's positive vibe and chemistry. She said she loves that I'm such a sweetheart.

The day after an interview that she told me about, I didn't have a chance to chat with her properly as it was a busy day so towards the end of the day, I went into her department and sneakily put a sticky note with my number on her desk right in front of her and asked how it went. She hid the note, chuckled and texted me right away and told me that she got the job and will be quitting soon. I was happy for her. A brief chat followed and then she went quiet. It was a very casual chat anyway so I didn't think much about it.

A few days later, she came into my department, tapped me on my forearm and said to me while completely ignoring all my colleagues, that she's come in to say goodbye, she's leaving that day (she was still on probation so she could walk straight out). She put her hand on my forearm for awhile and said that she has my number, keep in touch, she'll text me and let me know how it goes. I was completely flat out with work at the time plus with all others present, there wasn't much I could do so we said a simple goodbye. At lunch I sent her a text saying in a light-hearted way that my plan of strategically casually bumping into her later is all ruined but I'm well chuffed for her, that I'll miss seeing her at work and maybe we can start seeing each other outside of work. Then for a few days she hasn't even read the texts but she's been online so clearly she's been texting someone/people. Surely she's read it through the notification previews I would've thought.

It seems to me that she's holding off in responding as if she's thinking about something given the fact that she deliberately doesn't go into the chat and read it? Any thoughts? I think I've made my intentions clear?