Specs say 8gb onboard memory. I wouldn't assume that ("onboard") can be upgraded. [Edit: the Q&A says ram is not upgradable.] As long as it is light web browsing that'll be okay, but if your wife is a 100+ tabs person then more ram is called for.
These days 3lbs isn't exactly light. Light is pushing 2lbs, often at the 11-13 inch range, and you pay for it. YMMV if it is worth it.