Lets see - lower income with DW staying home plus higher expenses from new baby = change of plans.
However, you do have some control over how the plans change such as reducing some other expenses that you have (cable, eating out, housing, etc.), managing to a few extra years of working, increasing your income, and so on....
My DW dropped out of work for 5+ years to stay home and while we saw a number of expenses increase such as groceries, activities, school costs, health care, etc we ended up cutting a number of expenses such as
- we stopped eating out (who wants to with kids anyway),
- we became more mindful of our shopping (Target was a silent killer of savings),
- downsing from a 4bd 2400 sf house with finished basement to a 3bed 1800 sf house without a basement (reminder about 3 kids here) but it resulted in reduced utilities and taxes.
- there is more that we have done and honestly there is more we could do
Oh yeah, because she was home and managing the hardest job in the world I was able to invest more in my job because we weren't both running around like mad with two jobs so my income ended up increasing along the way.
In the end it did delay the plans somewhat particiularly because of the "Choice" to live in the area we are in and the cost of the activities/sports that they are involved in.
In some regard, I (and you and everyone else with kids) is trading some portion of your FIRE to fund the FD (Financial Dependence) of your kids (typically 18 or more years).