I would get her checked out physically in the first instance. Have you asked her if it hurts, and if so, where? If her throat is still irritated or she's having lingering oesophageal pain from vomiting/reflux, that could be making her more aware of the sensation of swallowing/food going down. In the meantime, could you push the "soft food" a little by providing food that will go down soft but has a little more form to it? I'm thinking soft cooked noodles, scrambled egg, mashed but still slightly lumpy starchy veggies, etc. Keep offering slightly firmer food but give her the soft options as well. Maybe she could take a smoothie or a fortified drink to school. You might like to consider giving her something to help repair her digestive tract, yoghurt with extra probiotics added, slippery elm, manuka honey to soothe her throat. I would be asking her too about what happened the first time she felt like she couldn't swallow, or if there have been any instances where she felt like she was choking or that she wouldn't be able to breathe (I'm thinking of things like a panic attack, a bad dream or an episode of sleep paralysis, or she didn't chew properly and swallowed a big lump, which can hurt, or a time when she had a bad cold and felt stuffed up). If you can get an idea of how/when it started for her it might give you some clues as to what is going on. But I would definitely get it checked out as well.