Ill At 7 mo., now 3, can't talk, walk, hold head up...

My daughter got interception at the age of 7 months due to the continuous vomiting.after a few day of the operation the burst abdomen occurred,after which she got sepsis followed by septic shock.After a few days meningitis appeared and the blood platelets were reduced to the lowest level .then she was shifted to ICU for further treatment and she recovered from all these problems But the Matter of Concern is that at the present age of 3 years She is unable to Talk, cannot hold any thing in her hands and the worst point that she can not even sit properly rather than moving and walking of a child at this age.
physical constitution:- She is normal not healthy but no obvious problem.
Growing normally Not holding her head
She is improving in supporting her head about 50%but still some times she could not hold it properly.
She can not sit without any support.usually using couch or some thing behind her back.
she is efficient in identifying parents and her toys and things which she use and when pointed to some where she looks their properly and hear properly.but can not speak properly but produce voices.
She has normal saliva but the fluids come out of her mouth regularly.
upper and lower body is OK.she cannot maintain her self to move and walk neither can turn to another side but struggle for it.
lower limbs r weak but it may be due to weakness and the movement of legs is OK.
paw fingers are curved inside when we try her to walk or to stand on foot.
a different type of smell in her urine.
Regarding This Matter i want your Expert opinions so that she could Live a Healthy and Normal life.
Please Guide me in terms of medicine and excersices by which i can give a platform to my Daughter for a Healthy Life.Thanks