KeyLogger or Windows Access

Good morning folks, i need a little help. In short, my wife is cheating on me but I need to gather some evidence from our computer prior to filing divorce proceedings. However, she has changed the password to the computer(Windows *0) and won't give it to me. She keeps the laptop, her phone and the iPad all on severe lockdown(like it isn't noticeable). I've tried having conversations with her but she won't admit to anything and berates me for questioning her fidelity.. We don't have any kids, but she stands to gain quite a bit due to a very sizable inheritance i'll be receiving in the next few years I would assume so obviously she doesn't want a divorce. Nonetheless, my question is this. Is there a way to access the password to Windows or remotely install some type of keylogger so I can see what's being typed?I could also try to use a program to access texts, IM's, etc. on her iPhone but I don't have her iCloud credentials or email credentials. Any help would be much appreciated to point me in the right direction.

Thanks in advance!