Yes, you can find differences between brands. You will even find that, within the same brand, not all shoes are sized the same way.
Products with specific women's sizing usually include the wording "W" or "WMNS" in their name.
We recommend that you always check the equivalence between the European and American systems, since it may be that you always wear a US 7 women and that, by mistake, you end up buying a US 7 men or vice versa. Verifying the equivalence you do not run that risk.
If you need any further information, please contact our Customer Service.