My partners daughter has frazzed her mac book pro due to water damage and has been told that the data can be recovered for £?????. I can remove the hard drive myself and my partner has a mac book pro so can I obtain a cable (SATA?)and hook up the removed drive to the working mac book pro?
That's a good plan. You can inspect the drive and see if it got wet, allow surface wetness to fry thoroughly before attempting to power it up.
As long as it spins, you'll likely be successful in recovery and might not even need something like Data Rescue to perform an undelete or partial recovery if the catalog is damaged.
Rather than a SATA cable, you could use a 2.5" SATA / USB case or enclosure if you are planing on using a MBP for recovery.
Unless you'd like to replace the internal HDD with the damaged one and move the data to another destination. As @bmike suggested, inspect the HDD and do not connect if it is wet.