All of a Sudden.

So, my friend (who is actually my friend not a ploy to not sound pathetic), met a guy three months ago and was super happy. She's a really close friend of mine so obviously I was happy for her. They text quite frequently, but a few days ago she comes up and tells me that he said they should take it slow because he wants to make sure he's not missing out on anything else. I was completely stunned that she didn't say anything and just said 'ok'. Was I overreacting, or is she being stupid for not seeing his plan?