Bringing in Prescription Meds

Hi all,
My girlfriend is coming into the UK on the 29th for a planned 5 month visit. She is on prescription drugs for depression and ADD and has obtained a prescription to cover the visit from her doctor but scanning the info today I noticed that the UK only allows 3 months of prescription drugs to be brought in through customs.

What is the best course of action for us to take? I've been taken off guard by this news as I've taken prescription meds in and out of the UK and USA without declaring them and never being stopped. It was only coincidence that caused me to spot the potential problem.

Should we return to the doc and ask for a three month prescription with covering letter for customs and then seek out a doctor willing to issue a private prescription in the UK to cover the remainder of the visit? My GF's doctor says he could recommend an UK doctor if needed?

Have I read it right, is there really a 3 month limit? Could we just bring the 5 months meds in or will all of the prescription be confiscated?

Am I right in assuming posting the remainder is a big no-no even if accompanied by customs declaration and doctor's note?

We want to do this exactly right as we intend to apply for a fiance visa when she returns to the US in July, and can't afford any hint of wrongdoing however grey the area.

With thanks for your time
Ant

I brought 6 months worth of my prescription with me when I moved here to the UK last month. I didn't know how long it would take me here to get set up with a dr. and all, and didn't want to have to worry about sorting all that out too soon, so I just made sure I had enough refills to cover me for a good while. I had them in my carry-on and no one said anything to me when I left the US or arrived in the UK, although my bag was never searched or anything (just went through the scanners while going through security before my flight) I don't know anything about the rules on this, and hopefully someone else will see this who knows more, but I would guess that if you want to be extra careful, just have her get a note from her doctor that she needs these prescriptions, in case anyone wants to know why she's bringing them in with her.