If your family isn't lamenting the lack of monetary ability to do XYZ that you wish you could be doing, then I'd say you aren't saving too much.
Are you saving "more" than you "need to" for your current plan though? I'd say quite likely. I put the following into FIRECalc:
Spending $54,000/year ($4.5k/month).
Current savings $0.
65 years (20 years pre-retirement to take you to age 50, 45 years in retirement to get you to age 95).
Retiring in 2037 (age 50 for you)
Adding $48k/year until then (your $36k/year current plus your planned $12k/year additional moving forward).
The results came back with:
Now, that doesn't include your pension, or SS (if you or your husband would have it), or your current investment balances (presumably greater than zero), etc. and to get that down to a 95% success rate I still had to pump up the spending by another $10k/year.
So, I wouldn't say you're saving too much, but I would say your current stated goals and spending support a lower savings rate than you're saying you'll have moving forward, especially assuming your current balances are likely greater than the $0 I was using to get those numbers..