Yes! Your child does not need to speak your home language fluently in order for it to be helpful. The bilingual brain benefits exist for children who hear and understand two languages – perfectionism is not required!
For some parents, they feel their child should speak the home language perfectly or not at all. By letting your child get comfortable hearing and speaking it, they may take more interest in overcoming the grammatical mistakes. Again, if the child speaks some of the language, they may be able to get the many benefits of bilingualism.
Should your child become more fluent in the language, they may later test for World Language Credits, which count toward graduation. A student may receive some credits for partial knowledge, while other students will receive the full four (4) credits and a Seal of Biliteracy on their diploma.