I cannot determine the origin and/or value of your rug without having pictures of your rug. I do need to know the KPSI (Knots Per Square Inch) on the back of your rug. Just count the number of knots in 1 inch and multiply it by itself. The other factors are:
Type material used in your rug (Wool, Kork [baby lamp wool], Silk)
Proper Size of your rug (You should measure the exact Width and Height of your rug).
The other factors involved are:
Where did your mom buy the rug? Local dealers in the US or IRAN? If you are not able to send the above information, the other good option is your local rugs dealer; they are able to give you approximate price of your rug for $45 to $60. That is a good investment if you are looking to sell your rug to your neighbor. You can get more money for your rug if your rug is in descent shape and coloration. My email is Afshin@oldcarpet.com if you want to email the picture or if you have further question. If you need more information about TABRIZ rug. Check:
http://www.oldcarpet.com/tabriz.htm
I hope I answered your question properly.