Asked her to be my GF after 4 months and got hit with silence

I’ve been seeing a girl for about 3 or 4 months, and since we both mutually liked each other, I finally confessed my feelings during a lovely night together and asked her to officially be my girlfriend, but she avoided giving a straight answer and left me hanging in total silence. Now I’m stuck in this massive cloud of uncertainty, wondering if she just needs more time to process things or if she is intentionally keeping her doors open while keeping me on the hook. To make matters worse, she constantly brings up her ex in our regular conversations; they are still close friends, which I know can be normal, but she is so plugged into his daily life updates that it’s starting to make me feel like a third wheel in my own dating life. Is this awkward silence and the constant ex-talk a genuine red flag, and has anyone else who has been in this situation before got any brutal honesty or advice on how I should handle this?