You can check out the amount your employer will pay for your wife by looking at your last payslip. The max. monthly amount the employer will usually pay for an employee and his families
health insurance is currently EUR 236,91. Therefore, if the share for your own health insurance being paid for by the employer is below this amount, the employer will take over the costs for your wife's health insurance up to the total remainder of this amount.
Example: Your own health insurance costs 300 EUR per month. Your employer currently covers about 150 EUR per month. this leaves a max. amount of 86,91 EUR per month your employer will cough up for your wife. If here insurance is for instance also 300 EUR per month, you would have to pay yourself 213,09 EUR.
Therefore it would be wise a) to have your current insurance checked for improvement on the cost side (change of coverage, higher deductibles, change of insurance to another provider) and also for your wife's future insurance you can juggle the premium with those factors (coverage, deductible etc.) to an amount less costly for you. For this you should contact an independent insurance broker, they can provide you with these detailed information and can also provide you with comparative quotes of several insurances to choose from.
Cheerio,
Starshollow