A lot of sage advice from various BITOGers.
Truth is, since she is your stepdaughter, it's still best to consent with your wife to ensure that she's on your side, no matter how bad the situation may spiral out of hand (that way, she (wifey) cannot turn against you 1/2 way through the process.
There are many ways to skin a cat RE: locking down the account. While it is somewhat beneficial to lock down that way, unfortunately, unless you are extremely computer-savvy (and you know how to lock her account down with granularty w/o upsetting her or her activities), otherwise: consequences are follows:
a) she gets upset over you being overly tight on her security measures, then she resort to spending time over at her friend's place using their/her friends computer to gain access to the internet ...
conequence: lose control of her/the ability to monitor her entirely.
b) have a round table meeting with your wife by your side: and explain to her (treat her like and adult and have adult conversations with her, not just being commanding and such) and told her that while your only concern is her safety on the internet (prey'ed by pedophiles, etc.), have a written consent agreement for her to sign (give her time to think about it, just like an adult would) a written consent (with your wifey's co-signature to agreement, as a 3-party agreement) to install monitoring software on her PC.
You have to make the written committment that you all shall sit down w/ regular meetings (every 3 months or so, make time for it) as a light-hearted means of discussing the logs with her...sometimes, consult her for certain activities or new technologies (to keep her intterested in the converstation and keep the conversation light-hearted).
also: in your written agreement: make it absolutely clear that when emergency arrives (during log reviews by you), you'll have the right to call for a meeting to discuss and act upon it (and make sure she agrees with it).
That way, you can have the upper hand of the situation.
Also: if you or your wifey knows her friend's parents, and such, bring forth the idea of what/how you impose your control (logging/watching software) onto her PC and also let them know that this is for your kid's safely on the internet.
If they can agree with what you do and go along with doing the same thing with their kids then great! you have a close community support! otherwise, you'll be fighting an uphill battle.
Good luck!
Q.
