Hi
My total sympathy. DS had extreme food rigidity and was diagnosed autistic at 12/13.
Long post of advice below but main advice is: do not take advice from people whose children don't have food issues. Not only are they clueless and smug and relatively unsympathetic - they think you are pandering and if you stop, all will be well (it won't), more importantly, advice for normal eaters going through fussy phases if very different from advice for ARFID
Things that helped with DS:
Explain the key food groups and what they do for her
e.g.carbs for active burn off energy, so her noodles and pasta are good if she is going for a walk or run or swim or cycle ride next day. ( Emphasise how good her existing choices are)
Protein to build strong, lean muscle and brain power and iron to combat fatigue. Sounds like she may need more protein so let her know how useful it is for her body to eat chicken curry or spaghetti bol. Maybe try some protein rich pasta too.
Dairy for strong bones and teeth
Fruit for essential vitamins for healthy hair, skin, nails, good mood and vitality.
Relax as much as possible about variety. If she's eating from all key groups every day then she'll be healthy enough. Tell her this.
Build family meals around hers. Pasta twice a week spaghetti bol or carbonara, plus one broccoli (with fried garlic, sun dried toms and toasted pine nuts added to adult plates it's a really delicious dinner) so you are all eating the same. A mild chicken curry once a week too.
In the spag bol, add tiny amounts of additional veg pureed into the tomato sauce. Start with carrots, red pepper then add courgette and or one cube of frozen spinach. If there's no complaint, gradually increase quantities and finely minced veg.
Same with chicken curry. Add tiny amounts of red pepper, red or white onion, maybe red lentils, butternut squash, frozen spinach to the creamy sauce and increase fractionally over the year, use the same recipe 3 or 4 times to ensure she's used to it before increasing.
At dinner, put out all three food groups in serve yourself dishes (eg petit pois to scatteer on carbonara or shredded iceberg.) Often with sensory issues they might be finecwith eg petit pois but not more grainy textured peas, or be ok with crunchy iceberg but not semi- crunchy cos or romaine.
Go out to dinner if you can afford it. DS was more inclined to try a burger and curly fries at 5 Guys or noodle dish at a Chinese place or chicken korma at a curry house than at home. Never judge 'boring' choice eg Marguerita pizza. Act as if all choices are equal. If she likes a given dish, after she's had it a few times buy the ready meal version and finally cook your own recipe of it.
I was so worried about DS but I got calm and kept trying. Gor neurological children you need to introduce a new food about 20 times before they'll eat it. With autism it can be 200 or 2000. No exaggeration. Just explain what the food does for her and leave her to decide.
As too other people eating noisily, can you play music while eating, or let her have white noise on headphones?
DS is adult now and really adventurous in his eating habits. It was a very long process and looking back, one of the things I'm most proud of, helping him to overcome ARFID without pressure or stress on him.