Okay, you mention two different things. First you mention SMS, then you say "usual blue texts". Does your daughter have an Apple device? If so, that is iMessage, the blue bubbles. SMS, is a text message, green bubble, and those are controlled by your cellular carrier. Also, if there is an issue with iMessage, if you have a setting on in the iPhone, your iMessage can be sent as an SMS. It would seem there is an issue with your iMessage. That can be on your end, or on your daughters. iMessage requires you be connected to the internet (data) either wi-fi or cellular. The same on her end. Use the troubleshooting steps in this support document to verify your iMessage settings, and you can have your daughter do the same. However, it could be something happening for one or two messages and will fix itself. Internet could have gone down temporarily, etc. But here is the link. If you can't send or receive messages on your iPhone or iPad - Apple Support