My mom has COPD is 72 yrs old and weighs 65 lbs. Is a stomach feeding tube safe?

Safer than starving. Within reason, people with COPD who weigh more live longer. No procedure or treatment is completely risk free but in many cases the risk of the procedure is less than the risk of not having the procedure. This should be discussed with the doctor recommending and/or performing the procedure.
Yes... If this is what your mother wants, feeding tube placement is relatively safe. But, this will not cure her COPD and she will likely continue to have disease progression. You need to discuss with her whether or not she wants to be placed on mechanical ventilation since, once this happens, she will likely spend the rest of her life on the ventilator. If she says no to vent, reconsider feeding tube!