I took off 6 years of chemical engineering.
I started subbing chemistry and math. Eventually got a PT chemE job through a connection. Then a full time job at a competitive salary. I left with 4 years experience and a salary of 77k. Came back PT at 65k FTE and then less than a year later, 92k, so a good bit above my departing salary (but probably about even considering inflation).
It wasn't easy. I spent a long time just getting technician offers. A lot depends on the job market. Where I first lived, there wasn't much. Where we live now there are tons of options for contract to maybe hire positions so I think it would be a lot easier to get back in, as you can always work for Aerotek for a year to get fresh work on your resume.
Returnships are also exploding in popularity. Check out SWE's website- they list participating companies. See if there are any in your area. They aren't just for women.