Hi there. I'm not a Guider, but a Scouter, but I should imagine it is pretty similar.
The guiding/brownie website states that they are completely inclusive but I don't want to send her off to slaughter
I think it's fair to say we all aim to be completely inclusive - but, as with all volunteers, come with our own experiences / lack of experience, knowledge / lack or knowledge, confidence to tackle a new challenge / lack of confidence in our own abilities.
Should I call around all the local groups and see which one might suit DD better?
If it were me, I would try to find out a number for the local District Commissioner (or in Scouting it could be the ADC - Asst District Commissioner - for a Section - so in your case Brownies - or the ADC Special Needs. I would have a chat about your dd's abilities and limitations, and ask them which particular pack they thought would be the best one for her. I know in my area, I field these sorts of calls all the time, which means I can a) point the families in the direction of the packs I think would be able to give the best experiences to your dd, and also, be aware of her, and go down to meet the Leaders and offer what advice I could.
That said, you - as her parents - are obviously the experts on your dd and whereas I could offer lots of general advice about working with a child with autism, you could offer specific advice about what works for your dd.
Are there any groups that are specifically for disabled children?
In our County, we do have Groups specifically for children with disabilities - 2 of which run within school time, at special schools, and one of which is in the evening. Not all Counties do have them though as some people feel they are excluding dc with additional needs.
Can I pay for her to have a carer attend to help her?
Yes, a carer would be very welcome - subject to normal dbs/Scout Association safeguarding procedure. You may be able to get this funded by an organisation such as KIDs (or ask at SCOPE?) or through 'Short Breaks' (although I can't get our Local Authority to fund this).
If I explained the issues would the leader perhaps be happy for me to stay each week and help DD as well as the rest of the group?
Same with you staying - you would need to be checked through normal safeguarding procedure, but I feel that parents of the child shouldn't have to be asked to stay (unless of course they want to) if no other parents are asked to stay. It might well give the Leaders more confidence if you offered to stay for the first 6 weeks or whatever though.
but I don't want her to continually have to explain why she cant eat whatever they've baked or why at 7 she still needs her Mum to accompany her to the toilet
I've worked with Nurse Specialists who work alongside dc and families with all sorts of different conditions, and they sometimes suggest - if the dc is comfortable with it - explaining to the rest of the class (or in this case, pack) a little about the condition in the first place. Obviously this is only with the child's permission, but I know of several dc who have found it to be really, really helpful to them - the other dc listen, tend to be very accepting, and then just get on with things. Up to you if you think this would be helpful or not - I know some parents are horrified, but others think it's the most practical solution ever.
The mental and physical disabilities are actually the least of her worries as her biggest one is the fact that absolutely nothing works as it should between her mouth and her bottom. She can't swallow, eat, drink or poop without a multitude of medicine
I wouldn't worry too much about this in the first instance. I'd worry about the weekly meetings first and see how she likes it. Some packs only go away quite rarely, so it might not come up. Once she is a member of the pack and considered one of the crowd, then people will be all the more determined to find a way to make it happen.
HTH. As I say, this is all from a Scout pov, but I'm sure it can't be far different. There are a lot of guiders on here though, hopefully we'll find some soon. 