Welcome to the forum!
Are you definitely maxxing out your 401k contributions? $1500/month doesn't add up to the 2022 max.
Your spending seems really high- esp. on utilities. If heating is so high have you looked seriously into improving your home insulation, etc (factors to decrease that bill)? Is your husband willing to go back to work or work part-time? Eliminate dining out (in our 3-person household we spend <$30/month dining out on average)
I am really interested in hearing more about your foster/adopt experience, if you're willing to share. Thinking about doing the same thing at some point potentially.
I'm crypto averse so my advice would be to cash in the gains and invest in index funds.
Based on your current expenses... I'm going to keep things REALLY simple here and go with an assumption that between supporting your kids into college, then funding their college, you'll average the same expenses you currently have for at least the time through you'll have your mortgage paid off, which you will still be doing if you retire by 40. Let's be generous and say you only average $6k/month in spending at that point. That means you need $72k/year. Going by the 4% rule that means you need a whopping $1,800,000 to FIRE on. Also consider the state of healthcare- it's a giant black box in planning for FIRE and we can't really bank on costs decreasing or stabilizing in 10 years (though I sure hope they do).
You currently net approx 67k/year after taxes, spending, and 401k contributions (120k net + 19k 401k -72k spend). That means you'll increase your NW by ~$603k in savings over 9 years. That, plus your current assets, brings you to only $861k. Do you expect the market to more than double in 10 years? That is what it would take to FIRE at 4% based on what I'm seeing here. Maybe the market WILL take off further, but I don't think you can count on retiring by 40 at this rate.
Perhaps this is an oversimplification of your situation (and finance planning in general) but that's the way I see it, and I like to add a healthy margin of error. The super short napkin math doesn't add up.
You're unfortunately not that close IMHO. BUT... if you are able to rein in the spending, perhaps find a healthy measure of college assistance (common for fosters/adopted kids in many states), and/or increase your income, you're in a good starting position if you want to accelerate a FIRE timeline.