Spendthrift clause or not?

My parents executed A/B Trust docs in 1990, just before my mother passed away. She made her three daughters beneficiaries of her 1/2 interest in the community property (real estate), with the remaining trustor (my father) holding the property in trust until his death. He is on the brink of death right now. He has amended his will/trust to change the manner in which the beneficiaries take his 1/2 of the asset (meted out over the next 15 years), but my Mother's interest passes immediately to her daughters (3 of us) upon sale of the property. The original trust docs have a clause, under the heading "Miscellaneous Provisions," the following language: "The interests of Trust beneficiaries are not transferable by voluntary or involuntary assignment or by operation of law and shall be free from the claims of creditors and from attachment, execution, bankruptcy, or other legal process to the fullest extent permissible by law." Is this an ironclad spendthrift clause or can I legally seek a small advance on my inheritance ($300,000 of which will pass immediately upon sale of the house...) through an estate or heir advance company?

You can always try...it is never 100% ironclad

Have a lawyer consult with you firstly...