Non iPhone shows up as iPhone to other iPhones

My daughter's cell phone is not an iPhone. However, when sending text messages, my iPhone thinks her phone is an iPhone. Unless I specifically turn iMessaging off, I cannot send her a text message. If I don't turn iMessaging off, my phone defaults to an iMessage. She has never received any text messages from me when they were sent as iMessages. Is there any way to fix this?

Thanks. Tried it, but my iPhone is still sending her iMessages.