She can do the conversion, but it will be largely taxable with a substantial portion of her basis in nondeductible traditional IRA contributions remaining with her traditional IRAs (including SEP and SIMPLE IRAs; SEP and SIMPLE IRAs are types of traditional IRAs).
Nothing about your wife's retirement accounts affects the taxability of your Roth conversion.
The limits on regular personal contributions to traditional IRAs are separate from the limits on contributions to SEP and SIMPLE IRAs (although salary deferrals to a SIMPLE IRA reduce one's compensation available to support a regular traditional IRA contribution). Additions to SEP and SIMPLE IRAs just make an individual covered by a workplace retirement plan which can limit the deductibility of a traditional IRA contribution
