Lots of older photographs lack a smiling subject.... the film took so long to properly expose back then, that it was very hard to hold a smile exactly right for that long. Much easier to hold a serious expression. LOL to me, she actually looks like she has a fairly happy-looking serious expression.
I agree with Grayceworks. She has a nice expression in her eyes. Maybe this was a present to a hubby who would come home and say "What did you do today?"
I wouldn't be happy either in that situation. Though I agree she looks like she's got something evil on her mind...throwing the whole bucket of water perhaps?