This doesn't seem right - malware?

I just emailed my GF and she instantly responded with a blank email reply. Since she’s sitting in another room I asked her if she had read my email and she said no. So, any idea what might cause this? Is her laptop infected? Is my PC infected? Both?

Out of office auto-reply?

Nah, her personal gmail account.

I just went and looked at it and in her Sent folder there are all kinds of commercial emails she has received that signed up for but would never forward to someone else that are being forwarded to gibberish email addresses. So I’m concerned.

Could you post some “gibberish” full headers? And take a look at her google dashboard and see if there are logins or any usage she doesn’t recognize.

https://myaccount.google.com/dashboard

A couple of extra virus scans on her machine in the meanwhile would not be wasted time.