The one that you can get in her favourite colour.
I have both. Super Tinker--bought one for $8 as a parts supply for a practically destroyed 1960s Fisherman I was planning to rebuild, since the seller said the Super Tinker had broken scales. Found it had hardly been used (and was not damaged as the seller had said in the item's description) , so I added it to my pocket right after cleaning at the time. As much as I like the Soldier 1961, I miss scissors and scale tools. The Super Tinker is my favorite thin 91mm. It has most of what I need personally. Explorer--I have one I bought used and the magnifier was part of the reason I bought the knife. It's really handy when looking at small stuff, like small markings on coins. Older ones, made pre-2005 have a much better glass 8x magnification lens and since this lens is smaller than the later versions, which were larger, they have a longer Phillips driver. The backside Phillips works well on smaller No. 1 Phillips well in addition to No. 2 Phillips screws, but the Explorer's in-line only works on No. 2 Phillips Screws. I personally prefer the back-side version. But, with the Explorer, one can put the eyeglass screwdriver (which works on No. 0 Phillips too in addition to eyeglass screws) into the corkscrew. I bought what was the cheapest at the time (before a slew of $20 old mag and hook versions were posted by various dealers), and got stuck with the plastic lens version that's 5x magnification. I like both, but personally prefer the Super Tinker.
I'd vote for the Explorer simply for the plus scales it can come with. With that said, since I've been wrapping gifts lately, it seems that a Manager can also be added to the mix.
I went with a black super tinker for the missus.