Of course!
The points you'll get for spending are nothing compared to what you get as sign-on bonuses. The offers come and go and differ by bank so what's available today may not be available in a month from now.
We generally do a bonus sign-up every 3-4 months or so (sometimes just one of us, sometimes both of us), which isn't nearly as hardcore as some real "travel hackers" out there but still has given us at least $15k in benefits in the last couple of years.
So far this year, I've gotten 80k in points from Chase (which is worth $800 in "cash" [ie. you just apply it as a statement credit to your account] or an extra 25% when you use it for travel [book your flights or whatever through the Chase travel portal, so $1000]. For that, we had to spend $5k in 3 months to get the bonus. We don't spend nearly that much on our day to day expenses so we just prepay things like homeowners/car insurance, or pay our quarterly taxes (self-employed). Others solve that spending problem by paying their mortgage (but there's usually a fee for paying with a credit card so we haven't tried that yet), or buying gift cards to grocery stores/gas stations etc. All of that is called "manufactured spending" by the way, so you can use that term to look up other ways of meeting your spending requirements. After you hit your spending, you usually get your points or miles posted the following statement. That particular card did come with a non-waivable $95 annual fee (always cancel after that first year so you'll only pay once) but that's a small price to pay for what you're getting in return.
Last month I got 50k points from BoA ($3,000 spending requirement to hit the bonus), which is worth $500. It came with global entry/TSA pre (which DH and I already got for free thanks to a different card, but baby girl still needed it) worth $100, and another $100 for travel spending (we just bought a $100 American Airlines gift card that we'll use eventually). It also had a $95 annual fee, but again, we're getting $700 for that one-time fee. DH just did one so far this year and it was for 60k Delta miles (worth a rountrip ticket to Europe).
We generally don't bother with bonuses that are worth less than $500 (in travel or cash), unless it's super easy to get the bonus (e.g. no spending requirement). There are certain rules of how many cards you can apply for by bank so it's not worth signing up for a crappy bonus that takes up a spot when a better deal might be coming up. Credit inquiries stay on your credit report for 2 years, so if you go through too many, it can negatively affect your score. We both have credit scores in the 800's so when you do it right, it doesn't affect your credit score.
That being said.... it's very important to keep track of your credit card application details. Start a spreadsheet! Add information like the date you applied for the card, details on the bonus you applied for, how long you have to meet the spending requirement (and add that to your calendar!), when you need to close your card (especially important if there's an annual fee, set a calendar reminder for that one as well!).
Also, make sure that you enroll for auto-pay and all of that. You don't want to accidently leave a balance and pay interest. Don't sign up for cards that have a high spending requirement if you won't be able to pay it off within a month, bonuses that don't require spending are around from time to time as well.
Doctor of credit is a great resource to find the latest bonuses:
Best Current Credit Card Sign Up Bonuses & Offers For June, 2019 - Doctor Of Credit
I don’t want to go back to work. I want to be a SAHM for a while. I didn’t think I wanted to but now that she’s here I’m like forget work!! Maybe I can find enough freelance work to stay home 
I'm also still thinking girl. With the genetic stuff you got done you'll also find out if it's a boy or a girl because, here in the US at least, they test for sex-chromosome linked diseases (they'll keep it private if you ask them to though, but you could give the results to your sister). Glad you're feeling well 
