I tried to email directly to you, but the email on file didn't work. You can email me directly if you would like.
Is you father still alive? If so, he might have the marraige lisense which should list both of your grandparents names. If not, records are a matter of public record and you will be able to look that info up. Try the county records in the town they were married. Some records are available online if you search.
A death Certificate would also be available for your mom. That is also public records, and would list her place of birth, parents names etc.
A lot of Lacombe's were Roman Catholic, and the church has kept meticulous records on marraiges, births, deaths etc. If they were married in a Catholic Church, that would be a great source. The Diocese probably would have the records.
If you could find out the names of her parentsand/or grandparents you will find that a lot of geneologist on this site could share your line information with you. Once you get to the individuals that are possible living (within 100 years) it gets more difficult. You might run into privacy issues with your mom's siblings, if they are still living (or believed to be living) info isn't released.
Talk to your sisters especially, we women tend to remember bits of info and they might remember the Aunt, Uncle, Grandparents, or your mom might have mentioned stories about them.
Did one of your sisters "inherit" a family bible perhaps? A lot of families entered the family tree into the first pages of the bible. There may also be some old letters too. I was given letters that my mom wrote to Aunts and grandmother. They even saved the envelopes!
If you know her brothers first name, have you tried to people search him? Fortunately males retain the surname and it may be easier to locate. Did they too live in NJ? Did her parents live in NJ also?
If you get frustrated in your search, email directly or post.