What you need to tell your wife that by coddling your daughter, she isn't doing your daughter any favors. By coddling her, your wife is stunting your daughter's emotional growth.
You are very generous offering to pay for your daughter to get help with her issues. However, you need to tell that this is a one-time offer. Take it or leave it. Either way, whether she takes it or leaves it, she still needs to find a job and start saving for an apartment of her own. Don't fall for any manipulations, like when she cries.
Also, don't put up with excuses like "This job is beneath me." Let her know that no honest work is beneath her. When I graduated college, the job market was bad and I ended up taking a job at minimum wage.