Do you mean the $500 credit for other dependents? You do not get stimulus money for claiming your step-daughter since she is over 16 years old.
You might get the $500 credit if she meets the criteria.
CREDIT FOR OTHER DEPENDENTS
https://ttlc.intuit.com/questions/4499708-what-is-the-500-credit-for-other-dependents-family-tax-credit
https://ttlc.intuit.com/community/children-dependents/help/what-does-financially-support-another-person-mean/00/26532