Skirting wonky and not straight. How can I make it look neat

[Swoph]

Hi there. I am in the process of decorating my daughters first bedroom and it has the worst skirting in it EVER, it is lumpy and wonky and everything bad you can think of. In one place is gets so thin it is almost flush to the wall! I have painting her walls green and the skirting white (both matt if that makes a difference) and even though I have painted without "going over the lines" it looks really higgledy piggledy - does anyone have any ideas how I can make it look nicer? We rent so putting fresh skirting on is not an option. It was suggested to me to put a border around it but I don't want a wide border or anything with pictures on. I suppose if there was such a thing as a white 1cm tape border I would happily use that but I don't know if anything like that exists. The wallpaper is also a textured stripe pattern if that is relevant.

Thank you so much for your help, any suggestions would be greatly appreciated.

 

[alan333]

If it's big gaps behind it then fill with caulk and paint with either skirting colour or wall colour, whichever would look nicer

 

[RogerBoyle]

Do you mean the walls have been re plastered with the skirting left on???

If so I really don't see what you can do about it