Her outfit takes clear inspiration from various articles of Uniform Modell Äldre ("older modell" collective term for all uniform articles older than Enhetsuniform m/1906, but is more practically used for uniforms from the later half of the 1800's). Extensive Wikipedia-fu helps me identify the possible article Vapenrock m/1854 for her coat and Kask m/1887 for her custodian helmet.

Vapenrock m/1854 was the only one that I could find with double buttons and a yellow trim, however it doesn't have a yellow trim on both sides of the buttons like Gotland has here, but that is likely artistic license taken for the sake of that bottom flap that covers the skirt. The rest of the coat has obviously been shortened in order to expose the skirt.

The shoulder flaps are also not featured on m/1854, but is a feature on other coats, such as m/1886 and m/1895, but I'm leaning more towards m/1886.

The colours combinations of the collar, shoulder flaps, galloons, pipings and insignias tell of what unit she belongs to. There's no point in trying to figure anything out from this and the artist is likely ignorant and has taken plenty of artistic liberty with it. I couldn't find anything that matches.

I don't know that that yellow thing with two buttons in front of her neck is. I haven't seen it on any uniform and it seems pretty redundant.

The ends of her sleeves don't match any uniform I could find as they are a different colour and lack details such as trim and galloons/pipings. However, her sleeves are quite short, so it's possible that she has folded up the ends, exposing the inside.

These are all army uniforms, btw. I couldn't find any navy uniform that looked anything near this.