If An iPhone Is Powered Off Will It Still Show The Messages That Were Sent To It?

My Girlfriend Recently Got Her Phone Took Because of some altercation, and i'm guessing her mother either turned her phone off or she just either, let the phone die. My question is. I sent her thousands of messages. Will they still show up when she gets her phone back? Or was I wasting my time

Yeah she will receive them the next time she turns it on

Once the phone gets turned back on, she will receive all the messages you sent