Does your "mum" live in Spain or the US? The reason why I ask is because here in the US there are certain groups you can go to for senior citizen discounts on computers. Some you have to be a member like AARP.
I used my AARP membership to get a discount on my computer through my Apple dealer.
If your "mum" lives in Spain, then I suggest that you also contact a couple of the many
User Groups you have in your country. Hopefully, one or more of them can recommend some Apple dealers that have senior citizen discounts.
If they are like the US, the Apple dealers will not advertise the fact that they do. Seniors must "ask" if the discount is available. These discounts are through the dealers & not through Apple.
Like the previous poster already stated, call Apple
first.