A-ha! I
knew I smelled a WeightWatcher!
I just read the post from the other day and I can vouch for WWers experience!
I lost 80 lbs with WWers and kept it off for years... but the last 2 years I followed it, NOTHING happened. I didn't lose ANY more weight, and I was eating very simliar to how your wife is losing or not losing now. VERY similar.
I basically had to be dragged into weightlifting by people who were telling me THAT was the change my body was changing. On the other side, I still went to WWer meetings -- though I was eating more protein and eating a little more food than they told me to -- and when I'd talk to WWer women, they said the same thing your wife did: Why are you weightlifting? You'll bulk up! You'll be so big! OMG, you're eating too many points! You'll gain!
And one month later... I was 5 lbs smaller, losing inches like crazy like I had in two years... and I was beginning to believe in the FitDay and higher-protein and adding-weights way of life. But that WWer mentality tells you otherwise! That was the flaw in their program -- they have all this emphasis on cardio and cutting calories and avoiding temptation... but they don't stress strength traning nearly as much as they shoudl, which further fuels the "I'll bulk up!" fear women have.
I've been lifting for a year now... I don't look like a man

I look more curvy and lovely as ever.
Wow, I just TOTALLY empathize with your wife! I didn't have a baby, so I would listen to Daisy and GG with their comments especially on that... but I KNOW what those WWer points can do to you!
Lastly -- I don't eat 6 meals a day -- I eat 3 main big meals (B, L, D) and an evening snack (all protein and good fats, before bed). On the weekends I'll have a midday snack... but you don't have to eat frequently to get all the fuel.
I'm a school teacher too. I KNOW what the daily timeline can be like!
++++ vibes to your wife. I hope y'all can figure out a convincing plan for her.