There's quite a lot to unpick here.
Firstly, Paediatricians aren't always the best to advise on education placements. Does your daughter currently attend a Nursery ? Or have a portage worker? Who is supporting her there ? What is their feeling ?
Secondly, does she have an EHCP (Education, Health Care Plan) finalised ? or in process ? Or been discussed with you at all ?
Thirdly, 'I would try to get the placement that suits my dd's needs first and foremost, and then sort the wrap around school care after that. I wouldn't 'not' send her to specialist provision if that was best suited for her needs, because I might have to look a bit further for wrap around care.
Fourthly, no-one on here can say if mainstream with support, would be better for your dd or not. We obviously don't know how significant her needs are, and nor do we know anything about the options available. There are some fantastic, inclusive, supportive mainstream schools out there, there are some pretty awful, exclusive schoools out there, and there is every measure in between. Some authorities have more specialist places per head of population than others. Some LAs have 'one size fits all' special school and others have different provision to meet different needs. It isn't as simple as 'mainstream vs special'.
I would try to clarify with her Nursery (or whoever is supporting you) what her developmental levels are. What her rate of progress is. What her developmental profile is like. How much support she currently needs. Where staff there feel she might be best suited to. GDD is a real umbrella term - one that covers a huge range of need, and one that is sometimes a 'holding place' whilst other assessments take place.