Fenom is one of the most widely recommended womens bjj gi. Not sure if it's judo competition legal, but they aren't too badly covered in flowers and stuff, so depending on your school, they may be acceptable. http://fenomkimonos.com/products.html
atama makes a fairly popular ladies gi as well.
Fuji, which is a long standing brand in Judo and BJJ Gi's makes several women's gis as well, some would probably never be allowed in a traditional aikido or judo dojo, but some perhaps would. http://www.fujisports.com/product.aspx?productid=95&pvavID=661&qty=1
This website has a review / list of bjj companies that market to the ladies:
http://gireviews.net/womens-gis-and-kimonos/ in the comments you can see discussions on which brands are just re-labeling their men's products and which are actually cut differently.
I wouldn't recommend trying to sew one yourself, especially a judo gi, the material is so thick, you need an industrial strength sewing machine for it. Tailoring a pre-made one would be tricky to.