My aunt recently passed away and I was named the trustee of her trust.
Her home is being sold for $660,000.00 and I was going to ask for a fee of 1.25% of the total sale. Would this be considered a reasonable amount as the trustee of her trust in the state of California?

Keep in mind that whomever you are "asking" this of are the other heirs to the estate. Assuming these are your family members - the issue of fees is fraught with emotional risks. My advice is go easy on fees, as whatever you take from the other heirs will not go unnoticed, and will cause resentment - guarranteed. One of the reasons people name family member to be executors or trustees of their estate is to avoid exorbitant fees that would otherwise go to "professsional" trustees - bankers, lawyers, CPAs, etc. I don't think anyone would have a problem with you reimbursng yourself for your own costs - travel costs for example. But the other heirs in your family may get a bit annoyed if they see you pocketing $10K or so, even though you will have to invest a lot of time in being the trustee, My advice is consider your time a gift to the family, especially since you are not a professional.

In most states the legislature sets a maximum fee schedule for handling estates. Those schedules tend to be very, very generous, as you might expect considering that the schedule is set by lawyers (the legistlature) for the benefit of lawyers (professional trustees or probate attorneys). In CA the statutory fee is 2% + $3K, or in this case about $16.2K. That's the max anyone would charge - if you were to shop around you would find that many (most?) profesisonals would actually charge less. Given that you don't have the overhead or profit requirements of a professional, In my opinion you should not be thinking along those lines.