If you have chosen a baby shower theme and then suddenly find that a close friend of the mother or family member have also chosen the same theme then it could put you in a bit of a fix. You may like your party to have a unique theme and to think that someone else has similar then this could be upsetting for you, especially if you have spent a long time planning every detail and the mother likes things to be special.
However, just because someone has got a similar theme to you, it does not mean that your parties have to be anything like the same. If you think about the guests for example. They will be different and so the atmosphere of the party will be different. Also it is unlikely that your decorations will be exactly the same or that the food or games will be the same and so all of these things will make it different. Some people do get quite worried about doing something the same as someone else that it might look like they were copying or they don’t like the idea of being copied.
However, surely it is flattering to be copied because someone obviously thought you had a good idea and if it is just coincidence that you have planned the same thing, then you obviously both had a great idea. It is too much work and stress to try to reorganise a party because you think the theme is too similar. Just relax, enjoy it and the guests will probably hardly notice anyway. It is all about pampering the Mother and so you should be worrying about that rather than the theme. If your theme is subtle anyway, then it will not be that much of an issue anyway.