Manufacturers like to make "grades" of such products with various amount of memory; while actually they are using only one PCB and usually one firmware, to spare some logistics involved in "personalisation". So, the hardware and firmware might be ready to accept one more memory chip - or not. It would be more likely if you'd (or your friend would) know, that the device under question does have also a "more memory" option on the market.

However, nowadays I would expect that in such case there would be a place on the PCB for the extra memory chip. In the old times of DIP chips, it was not uncommon to "mate" two such chips, with only the chipselect pin distinguishing which one is to be accessed - but it's not likely this will work with TSSOP or even BGA packaged memory chips.

Also, this would rely on the firmware performing check of available space. This might or might not be true...

All in all, I don't think it's worth the hassle, the probability of immediate success is low...

JW