You can file Form I-539 with USCIS to request an extension of your B-2 stay before your I-94 expires. Traveling to other U.S. states is allowed as long as your status remains valid.

Make sure to submit the extension request as early as possible and include evidence of the family reason that requires you to remain.

Provide proof that you can financially support yourself without working and that you intend to return to the Czech Republic when your visit ends.

While your application is pending, you can stay past the original expiration date without accruing unlawful presence. Keep a copy of the receipt notice in case authorities question your stay.

If an extension is not granted, consider whether you qualify for a change of status, such as switching to a student or other nonimmigrant category, depending on your plans. Be careful not to work or violate the terms of your B-2 visa while waiting.

Internal U.S. travel, like moving between states, does not require special permission, but always carry your identification and I-94 record for proof of lawful status. Consulting an immigration attorney can help you explore all possible options. Acting before your I-94 expiration gives you the best chance to stay legally.