I agree with building the best ever links with parents and other carers. Parents will have the most intimate knowledge of their child and working together will help overcome problems and enable you all to share times of celebration.
A few aspects you might find proactively informative ..
learning and being with children
Behaviour and possible reasoning behind the use of avoidance strategies
High palate/mouth roof - possibility for food to get stuck, chewing and moving food around for longer before swallowing, also impacts on speech and drinking.
John Langdon Down's syndrome information on NHS.uk
Grooves - routines and a need for consistency or continuity akin maybe to elements of schema & ordering a world? link is also to downs-syndrome.org.uk
obsessions, repetitive behaviour and routines on autism.org.uk
Stimming
Hugs may be forthcoming, it's a physically demonstrative way to say hi, bye, I love you, I'm happy, I'm strong, I've had enough .. it's quite personal though everyone with & without ds is very different in how they express their emotions :)
Communication and language skills are of great importance:
case study on talking point
The
development journal for parents is a good read,
training information is available on the right of that page, maybe see what's available locally?
There are many debates surrounding screening, treatments, supplements, therapy, advice, getting to know your parents will open a window on a huge amount of opinion and thoughts xx
Best wishes