Hi Ditnc, I did read they are hereditary but a higher risk between siblings, as in your mother's case. I had a coiled ruptured aneurysm 5 years this coming april, and it was surgically clipped 2-3-10 (last week). When I had my aneurysm it was immediate and intense so I knew something was wrong. One of my mottos is "you know your own body" if it's not normally pursue it with your doctors. I had angels with me when it happened b/c I don't even know anyone who had one, didn't read or watch anything on it but out of my mouth to my husband with out thinking was "i think i just had an aneurysm". Went to hospital was confirmed by CT and spinal tap then found out I was a good candidate for coiling. 5 years later the neck of the aneurysm widened and i was given a choice to stent with more coil or clip. Did my research and decided clip, I also have a partial droop on my left side of my face. I was told it's not common for this to occur after 5 years and if there is a change in a coiled aneurysm then it is most common during the first 1 & 1/2 years and this happens but is unique.
Sorry to go on and on about me but the more knowledge you have on aneurysms the better you will feel about following through with your own situation. I never had headaches leading up to the rupture or recent physical changes just knew I wasn't right and follow up with Dr.
Remember "you know your own body" better than any doctor so pursue this to make sure it is not an aneurysm. This is your precious life you are taking care of...