Citizen of US, mother is a Dutch citizen but living in US for 25+ yrs

Hi, I am looking for information on moving to the Netherlands.  My mother is a Dutch citizen and holds a current Dutch passport.  But she has been living in the US for maybe 30 years, and has never filled out any other paperwork keeping her status current and is concerned that her citizenship may not be valid at the moment.  Is this true even though she holds a current Dutch passport?  The reason I am wondering is because my husband I would very much like to move to the Netherlands permanently in the next 3 years, before I turn 28.  I understand that I am a Dutch subject until I am 28 years old, but I wonder if my mom's negligence will effect my ability to become a citizen.

Any help is greatly appreciated, thank you.