Why do my texts sometimes come in as gibberish and unreadable?

[AC Question]

I have recently started texting with someone using an iPhone 6 and about half the time her texts come in with a bunch of symbols and hieroglyphic looking symbols. It doesn't happen all the time, and sometimes if she just forwards me the same exact text it will come through fine. I can't figure out what is going on! Anyone have any insight on this????

 

[dpham00]

https://support.apple.com/en-us/HT203428