I do not recommend.
Instead, encourage her to get involved with Bible Studies or communal groups outside of her church (I'm assuming she has tapped out that well already). There are many churches, organizations, or just groups of Christians that are welcoming to members of other churches.
Plus it probably has a much higher chance for a spiritual benefit than online dating.
*Edit to add context and personal experience:
I am 30 years old and have extensive (embarrassingly more than I care to admit) online dating experience. Yes I have met some wonderful people there and had some good experiences come from it. But the bad outweighs the good, and this is not just personal anecdotes - there is well documented research on the pitfalls and damage of online dating.
As texasaggie2015 mentioned, modern dating has lots of new challenges that weren't there in the past. Again, this is well documented and researched. So I feel for subject of OPs post. I was right there and probably could have been described in identical terms when I was 27.
Maybe she'll get lucky like me and buy a house next door to a gorgeous, caring, selfless, fun, doctor...
But if she has tapped out her friend network and church network - she just needs to expand that network. There are good guys out there and they're a lot easier to find and easier to form a true connection with if it begins in-person vs. online.