This isn't the sort of thing I find often, so this is just my best educated guess and I could use corroboration or correction, please.
The b/w stripes really looks 1910-ish to me, but the length of the dress looks 1916-ish to me. This is not a fancily made item. It is definitely old, but could it be a costume? The fabric is muslin, with the dress having two snaps at the back of the neck. The striped fabric and collar are very light muslin; the collar has embroidery. There is a large inseam at the (slightly high, at least on me) waist, with the very large inseam being attached to the bodice, not the skirt, which has a smaller inseam at the waist. The jacket has quite fitted sleeves.
The b/w stripes really looks 1910-ish to me, but the length of the dress looks 1916-ish to me. This is not a fancily made item. It is definitely old, but could it be a costume? The fabric is muslin, with the dress having two snaps at the back of the neck. The striped fabric and collar are very light muslin; the collar has embroidery. There is a large inseam at the (slightly high, at least on me) waist, with the very large inseam being attached to the bodice, not the skirt, which has a smaller inseam at the waist. The jacket has quite fitted sleeves.