Your daughter needs baseline workup: that includes hearing (audiology) assessment, developmental assessment, speech assessment: all with relevance to a 3.5yr old. If any abnormality detected, then even speech/language pathology evaluation must be done.
Next Steps
As you are luckily in Bengaluru, there are few good specialised centers (eg. Chandrasekhar Institute of Speech & Hearing, Lingarajapuram) which do a commendable job
Health Tips
Preschool age is crucial to rectify any defects if any: so please seek early expert evaluation