EOS 100D or M3 or better camera phone for my wife?

So my wife is looking to get a camera to photograph her cake business. Her mobile phone camera (Galaxy S3) just doesn't give enough freedom.

I'm thinking to get her either 100D, M3 or a new phone with better camera.
She'll be mostly shooting JPEG anyway & upload straight to social media, so post processing doesn't matter.

With 100D she can borrow my existing lenses lineup to take better pics, whilst still somewhat portable.

M3 is very lightweight & portable for her style, but it needs an additional converter to use my lenses. Plus the M mount lineup is still limited.

Mobile phone with better camera will probably be the most convenient option for her as there'll be less item to carry. But still don't know which Android phone has the best camera.

Budget wise about the price range of new M3 kit. So that applies to the mobile phone with better camera.

Any suggestions & inputs are very greatly appreciated.

For cakes and casual shooting m3 with a kit lens is better suited imho (I have both), wifi is also handy for uploads without a computer.
There are good 3rd party converters, which are a lot cheaper than the Canon's one.
You may also consider eos m10, it's a bit smaller, lighter and cheaper than m3.

Heya,

Frankly, for a little tiny web-sized JPG being uploaded to social media, where their algorithms further degrade and destroy the image, I would not put a lot of money/effort into it.

Instead of fooling with a camera and making that the center of what will create a great image for your wife of her cakes, I would instead focus on how you can incorporate lighting which is far, vastly, much more important than simply having a neat big sensor camera and/or fancy lens to create those little JPGs that will be altered against your will by every social media platform used.

If using a phone, that's fine, but if there's a way to trigger a light, that would make it totally great. Not sure if that's an option, an indirect off camera, light, not just the LED mess.

If using a small camera, that's totally good too. The EOS-M3 has Wifi. That lets you grab the JPG and send it straight on to social media. The M3 lets you use off-camera speedlites like a charm. Super simple. Nothing more needed beyond the 22mm pancake too. The G16 is also Wifi and can take off-camera flash too. Also worth exploring, far more simple for her to use, and has all the things needed to quickly get it to social media. I would go one of these routes, over a cellphone, simply due to being able to incorporate a good off-camera light.

A simple speedlite bounced with ETTL will be a big deal for a nice image that is not going to be processed. Versus a nasty cellphone image in what I bet is probably not great light.

M3 + 22F2 STM + YN622 + YN685 (ETTL)
G16 + YN603 + YN560IV (manual only)

Wifi, have a laptop/tablet/phone handy that connects to it and can do a quick crop and upload to social media.

Very best,

The only thing I would add to this would be constant light options. If she doesn't want to mess with triggering flashes, even adding the right backdrop and a few well-placed reflectors can make a big difference over just using overhead room light. Not to mention LED light panels that could just be turned on independently of the camera.

An SL1 is quite small, and the ability to use all your lenses already natively is a huge advantage. This means you can just buy the body for probably around $250-350, and you are done, nothing else needed. You can also easily teach her the usage of the camera since it is fairly close to that of what you already have, and processing of the files works identically. Finally, the SL1 doubles as an outstanding travel/vacation camera.

Getting an M3 with an adapter that will affect AF speeds, etc coupled to large lenses seems like a bit of a waste, since the overall package is still already quite large once you throw the lenses out there, however it is indeed a good option.

Sure you can get more lighting and try to use a phone to take pictures, but honestly the look will still be the same. I assume like any other food business, eventually you will want full size brochures/fliers, etc, and having a bit more DOF control and the IQ of a camera and your lenses now would benefit that initiative. Having good appropriate lighting is a separate activity that is needed regardless of the camera you use, and isn't really a replacement for a good camera.