Yes, your family members can accompany you to Thailand. However, if they do not qualify for the Thai Retirement Visa (O-A or O-X), they can apply for a Non-Immigrant Visa O or ED (for the dependent child)
You can only bring your spouse or dependent child under the age of 20 with you.
Live your best life in Thailand. Get help with Visas, accomodation, itineraties, retirement, dating and anything else in Thailand.