Before you meet with anyone like this you need to make sure that you are on the same page with your goals. This goes for therapists, trainers, interior designers, doctors etc. The first appointment is just as much for you to see if you want to work with them as it is for them to see if they want to work with you.
Your body needs carbs and protein so I can’t imagine she eliminated them. There are carbs and protein in vegetables, beans etc.
It sounds like this person isn’t a good fit for you. I recommend spending some time thinking about your goals, why you think IF is for you, what gig are and aren’t prepared to give up and then find someone who can support you on your journey.
You may also want to check out OMAD. One Meal A Day. When you combine that with CICO. calories in-calories out you can achieve great results. The most important thing is to balance your foods. Your meal should have mostly protein, veggies and a minimum of starchy foods and fats.
What were you eating before? You can do IF with lots of processed food, keto, or vegan. Maybe she’s trying to steer you to more fresh whole foods. I’ve seen OMAD meals posted daily that are nothing but junk food.