Practically no difference between MD and NP?

I’m currently 20 looking to go into the medical field. I’ve been extremely interested in becoming a doctor. I’m specifically interested in psychiatry or pediatrics. My sister in-law is an NP, she claims that the only difference between MD’s and NP’s is the track that it takes to become one and that an MD can do surgery. My concern of taking the NP route over the MD is the lack in depth of knowledge, primarily for psychiatry as it’s a much more nuanced and tricky field. The fact that I can take a 2 year masters and be an “expert” in the field is just a little off-putting to me. I just want to be prepared for whatever field I go into. My sister in-law has stated things like “I’ve met really dumb MD’s and really dumb NP’s and vice versa” and “MD’s go to NP’s for help just as much as NP’s go to MD’s” while I was under the understanding that MD’s had a much much greater depth of knowledge than NPs and were much more capable of handling more complex cases and patients. I guess my main questions are, besides the academic path, what are the differences? Is it worth becoming an MD for the extra knowledge, is there even much more knowledge to gain? The last caveat is that I have a 6mo daughter, and the path of an NP is clearly much easier for raising a family and shorter, can I still be an extremely knowledgeable and impactful healthcare worker taking the easier path?