I just can't understand why this question provoked such a harsh response.

Maybe my response was too harsh, and if so, I apologise.

However, you may like to read this(just the latest of increasingly frequent warnings) and then consider if there might not be some reason why banks tend to make their login mechanisms difficult to automate? You say that you are not a security expert. Banks generally have a bunch of skilled people working for them, and they are very conservative in the provision of external access to their systems. Ponder why they are so.

You say you want to create a "family financial portal". Just be very sure in your own mind that you do not create a portal to your finances, open to a far wider audience.