Connecting a new ADSL socket --- illegal?

I said I would connect a new ADSL socket in my aunt's house. She has a two phones, one in the hall and one in the kitchen. To use her broadband she plugs a temporary 40ft long cable from her computer to the "master socket" in the hall.
I couldn't see how the kitchen phone was connected, so I checked in the loft.
There is a simple junction box at the end of the BT DROP wire with two lines exiting. One to the hall phone and the other to the kitchen.
I was simply going to add a third exit wire for the new ADSL socket I was going to install in her spare room.
However looking at the other posts in this forum there should be no break in the BT DROP line before the master socket. Therefore her existing installation appears to be illegal and my proposal would definitely be illegal.
http://www.tlc-direct.co.uk/Technical/Telecoms/Telephone_Wiring.htm#Top
seems to suggest the correct way to install.
Are my assumptions correct?

Thanks Mike

That is the way it's normally done these days. The NTE should be the first, and only connection to the incoming line. It provides a segregation point where the customer's wiring can be isolated from the network suppliers' wiring for line testing.
Does the installation have an NTE, or just a master socket?
Older installations, done before NTE5s came into use, and before broadband was even thought of, were often wired the way you have found.

'Star' wiring from a single point can limit ADSL performance because of multiple signal reflections from each cable end. 'daisy-chaining' sockets means there's only one cable end to worry about.

If the NTE5a is fed with a 6pair drop from the joint in the loft, you could use one pair for the live from the BT drop wire to the a/b on the NTE. Use the other 2 pairs for the extensions off the lower customer removeable portion of the NTE. Join these to your extension runs.

As a side note, ADSL is not neccessarliy a good idea from an extension socket if you live some distance from the exchange.

You could always relocate the NTE to the spare room, and then run extensions out to the other locations....

...Or plug the router into the NTE, and run cat 5 / cat 6 cable from router to PC.

If you want the best ADSL performance my advice would be to fit a NTE5 where the BT line comes in (if you can scavenge a BT branded one from somewhere so much the better). On this I would then fit a filtered faceplate to seperate the voice wiring and ADSL wiring.

This way any branches in the voice wiring won't affect ADSL performance.

I agree with Plugwash.
You do not even need to "scavenge" as NTE5 can be easily purchased.

With that old connection box, I do not think that BT will complain at the swop. (But a useful "thought" is that if the junction box gets accidentally damaged, -cracked or one extension cable loose--BT will swop it for a new NTE5 free of charge).

If the junction box is replaced with a NTE5 and adapted face plate (Total about £30) then the two existing phone cables can be connected into terminals 2 & 5 of the face plate and a CAT5 cable run from terminals A & B to an ADSL socket near the computer. This socket then connects to the router.
A spare pair in the CAt5 cable can also be connected into the terminals 2 & 5 and then if a double socket is utilised, a phone socket can be installed along with the ADSL line.

Result--no microfilters, separate ADSL and filtered phone circuits with maximised ADSL service speed.

This link and its related pages may help with ideas.
http://www.clarity.it/telecoms/adsl_faceplate_mod.htm

Thanks for all the good advice.
Next time I'm at my aunts I will take the top off the junction box in the loft and see just what wires are in there and their connections.

Cheers Mike