Have iron defiency anemia. My grandson had a brain avm that ruptured. Could I have an undiagnosed avm that causes this?

Unlikely. Its unlikely that your anemia is related to avm. If your grandson had an avm he was likely born with it. There are certain types of avms that run in families but other family members are usually affected.
Unlikely. The cause of your anemia is not likely to be from an avm of the brain. There are numerous other potential causes. These should be worked up. The other issue is whether or not you have a brain avm. Although there seems to be some increased prevalence of avms amongst family members, this is not necessarily the rule.
Not really. First of all, iron deficiency anemia comes from losing enough blood over a long period of time to drop your blood counts. This cannot happen from a brain avm or else you would have died a long time ago! second, you are not likely at any significant increased risk because your grandson had one.