One big issue to consider when deciding on inland vs. outland for PR application is travel.
If she applies inland, she must stay in Canada for the duration of the application process. If she leaves at any point, she may be denied reentry to Canada, and if that happens, her application is considered abandoned and you'll have to start over again. Keep in mind, the timeline is around 14 months for inland applications, but there are no guarantees. There are people who have waited longer. This means she will be unable to visit family and friends outside of Canada for a year or more. I know from personal experience that, while that doesn't sound so terrible at first, a year can be a very long time.
If she applies outland, she can can still visit you and stay with you on a visitor visa, and she can still apply for an extension to that visa (remember, she will not be "living" in Canada, but will be "visiting" you while her application is in progress). She may travel back to Israel to visit if she wants. The travel drawback with this option is that, if CIC requests an interview, she would be required to travel to Israel for the interview. This may be a consideration if funds are quite limited.
Personally, I deeply regret applying inland (I'm a U.S. citizen). I miss my family terribly, and I've spent over half of my only nephew's lifetime in Canada, unable to visit him. I'm 9.5 months into the process, which is currently taking longer than estimated. I should have stage one approval, known as AIP - approval in principle - by now, which is when they approve my husband as a sponsor and move on to my background check and making sure I'm elgible for PR. This was expected to take around 6 months, but a lot of us are waiting much longer right now. AIP is important for inland applications, as it affects eligibility for some programs. Some provinces will allow those with AIP to apply for health coverage. For me, I need AIP to be eligible for admission to an immigrant French program (I'm in Québec, and in an area of Québec where there are very few anglophones).
So that's my feedback. Only you and your fiancée can decide which route is better. As others have said, it doesn't matter where you get married, just that the marriage is legal where it is performed. Be sure to take a lot of photos, save invitations, etc. It's your responsibility to provide proof that will convince strangers at CIC that your relationship is genuine and ongoing. You're young, and you've only been together 5 months, so be proactive now and be sure to start building up the proof that you can offer. Good luck!
