Weaning can be really tough but please try to relax a little about this, it's your job to offer food, at 6 months it's totally up to her if she eats it or not and it's unfair of your HVs to put pressure on you.
I'm DF too, it's tough thinking if things prepare at first but it does get easier.
She's reaching for the food on her dads plate so I put some steamed veggies on there that he could let her have off his plate in the hopes she would try. Same reaction.. Is there a reason she is only being given fruit, veg and porridge? This is what you would normally offer to a much younger baby when Weaning. What was DH eating and why couldn't she have it? At 6 months she should be able to eat pretty much what you eat, as long as it's DF.
My DD hated the spoon and the high chair, I had to abandon the spoon pretty quickly and go with food she could feed herself. Moving the high chair and putting them in it with a toy, seems to stop the association with the stress of eating. Another thing that worked for me was sitting DD on my lap while I ate lunch. She'd play for a bit but usually end up eating some of the things.
If it were me, I'd not offer her anything for a couple of days, try to eat when she's not around or if you are eating, make sure it's DF and if she asks for some, then she can have some. This give you both chance to relax a little.
After that, stick her in the high chair, give her something to play with and let her watch you doing something else like washing up, or cut the grass. This should help take the negative association away.
Remember at 6 months, she only really needs to be offered solids once a day, and it doesn't even have to be every day. Just make sure she has a good vitamin supplement.
Sone things you could try her with are:
Breakfast: sausage cut lengthways with baked beans or blueberry pancakes made with almond milk.
Lunch: tuna sandwich with sticks of cucumber or omelette.
Dinner: Spag Bol, fish pie, toad in the hole, roast dinner. All of which can be made DF and all of which you can all eat together 
Let me know who you get on 