My exH has replied to a text message I sent DD - pretending to be her 
It is so obviously not from DD - no txt spk, punctuated, spelt correctly, and the language/style is identical to exH's pompous emails, and certainly not something that an 11 yr old would write or say 
The issue itself not a big deal - I only texted to ask if she would be dropping her overnight bag in before school when she walks past this morning - but the fact that exH has replied, with a cryptic and all-together unnecessary response, and signed it off as her, is bothering me hugely.
Should I talk to her about it? Ask her about "her" reply? Or should I leave it and let it fester as yet another reminder of why I divorced the arse him?