You must be responding to the post the Richard made.As far back as I can go - I am not finding and Jewish heritage.All the records have been from Catholic Churches and that is back into the 1700's.
It is very possible that Pons in some places became Ponce - many names changed over the years and depended on what country they were in as to how it got changed.
I have seen many Spanish surnames on lists that were supposed to be Sephardic Jews - but that does not mean that all of that surname were.
As to how to help you trace back to Spain - how much do you know beyond your mother? Do you know her parents names? Or when the family arrived in Guatemala?Or from what country?Did they stop anywhere before Guatemala?
Some Spanish families who wound up in the United States stopped for a time in Cuba, before progressing on to the Port of New Orleans.
Even family "stories" help - they do get "embelished" over the years - it's possible to find the clues there though, to lead you to the truth.