Hello from JustAnswer.
Yes, stress certainly can affect the ability of a woman to achieve orgasm, but there are a variety of other possible causes. The most common medical conditions that can adversely affect orgasms are certain problem metabolic conditions, such as diabetes or thyroid disease, and any condition that affects the nerve supply to the genitalia. Nerve problems can be either a problem that affects many nerves, such as a neuropathy or inflammatory condition, or a condition that affects only the nerve to the genitalia, such as degenerative disease of the spine.
There are also a variety of substances that can affect orgasms, both recreational substances, such as alcohol, and prescription drugs, with the more common drugs being blood pressure medicines and antidepressants.
In addition to stress, there are also other psychologic conditions that can cause a woman to not orgasms, with the other common condition being depression.
In a woman with new onset of difficulty achieving orgasms and no obvious cause, such as a recently started medicine, it would be appropriate to see your doctor for a general evaluation.
If I can provide any further information, please let me know.