First of all, I have to commend you for your work and its wide appeal. When I first saw this piece I was very ready to criticize it for its unoriginality, having seen many like it online in the past under the label 'modern impressionism' . However it seems that you sir have set the precedent yourself! So to call this style of painting unoriginal is not completely accurate. However, I still intend to give you my two or three cents, though I will try to avoid simple issues of good taste.
Whether you plagiarize yourself or another, it makes little difference to the integrity of your art. This subject matter is incredibly banal: A woman in the rain with highly saturated trees. This particular painting brings nothing new to the table. It is remarkably like every other one of your paintings.
The colors throw all sense of reality out of the window. They are completely fantastical to the point of being garish. Though I might compare this style of painting to the impressionists of the 19th century, none of the same values are there. While Monet was interested in the optical effects of color and light -- nature. You seem more interested in the artificial.
I don't believe exploiting the brightest colors possible everywhere in your painting is what will create beautiful, rich colors. Rather letting a few small areas of color sing against a more neutral plate will. Colors are relative. If everything were a little more desaturated, you would have more room to add accents of color that draw the eye to focal points such as the lady with the red purse.
I'm sure you are aware of all of this already though. My biggest critique is simply that this painting, though well executed, succeeds only in appealing to the most shallow emotions. It does not provoke any sort of intellectual thought. It is Kitsch. Now if that is your aim, so be it. But you do not need to resign yourself to painting the same work over and over. And I truly believe that your work can improve through study of nature. A rainy day can be very beautiful, but what you have painted would hardly be reminiscent of the real thing were it not for the umbrella and a few reflections.