Any advice really helps ! My 3yo girl loves putting things in her mouth.
As much as I know that this is a trait of asd (has your daughter been diagnosed?) it is also a trait of most 3 year old!
What sort of things is she putting in her mouth? Is it sensory seeking if so there are several chewable sensory toys available that could be offered instead this may alleviate some of the desire to put things in her mouth