While some items might be feasible (though getting Holy Water is a little tough) with some proper home cooking, magic in the Dresdenverse does not play well with technology. At all. Chances are that anything requiring circuit boards and such would short out upon contact with any sort of moderately supernatural critter. And the more jurry-rigged the device, the quicker it's going to fail. Especially when she starts hanging out with a wizard-in-training and a spell-slinging changeling.
Now, if you're keen on playing an inventor type you might start looking at the Ritual (Crafting) power. There's a ready made group in the Aurelianic Association if you want a group or need a tutor. Said items might even incorporate "technology," but in that case it would be more of a magical paradigm than any real technology.
And for just a few points you can really get a lot of one-use items. The Ritual power nets you 4 enchanted item slots, all of which are rated in power at your lore. An application of Refinement will net you an additional 4 enchanted item slots, giving you 8 total slots for only 3 refresh.
Which is one way to go. If you don't want to take a power, the types of devices you'll be making will be decidedly low-tech in approach. Think super-soakers filled with liquids, not flash bomb grenades. More chemistry and less engineering. Doing this would require a good Craftsmanship skill and probably a custom stunt.
That and I'm not saying that she can't create electronic devices - only that they're probably going to short out after one use, at best. More than likely they'll never really work when she needs them.