Lk. Stevens is locally known as a
very tough lake. I had some great results on Lk. Rossinger. I liked the 3rd section(far end)...try the mouth of the creek, there's a very nice dropoff, and inflowing water is almost always a very good thing. Also fish on the point opposite, and the heavy cover on the NW shore from there. Unweighted Senko or splitshot a craw or lizard should work.
Martha Lake was written up in H&FN in a recent issue, but I can't recall ever fishing it. Cottage Lake might be ok for the kids...electric only, I think. Lake Ki was mentioned in the same article. It's west of Smokey Point, on the way to Goodwin and Shoecraft. Not sure it's in Snohomish County.
Goodwin is a real good lake, but Shoecraft might be less impaired by water turds (technical term for Jet Skiis

), as the launch ramp sucks, or did when I went some years ago. Both are very clear, with rocky bottoms. Pray for clouds (that should be a good bet, of late), and use light line. Splitshotting 5" Zoom lizards (green pumpkin, mossy pumpkin, or watermelon) would be a good ploy, as would 4" and 5" Senkos in light colors. Both have LM and SM bass.
Flowing Lake is supposed to be good for numbers of keeper sized fish...electric only, I think. I went to the lake across the street, and can't remember the name of it. It was open to operation of gas motors, had a nice dock & launch, but it happened that I had the canoe that day. North of Monroe, past Rossinger (launch parking is a problem on Rossinger, so you have to be there early). I can't think of any other Snohomish County lakes I've fished that I'd recommend. I'll have to dig out a map.
C&R, Steve
(but keeping some small bass would be a good thing!)