No. The company should be able to provide expert guidance on this or point you at their advisor who can.
Income tax is due on the discount between the exercise price paid by your OH and the "true value" at date of exercise. The option to buy below fair market value gives her extra income, which is what's taxable (the value to your OH is the same as if they'd just increased her salary by the difference). So in your example, (€3.50-€1) = €2.50 discount *6250 units. CGT is then due on any subsequent gains between "true value" (e.g. €3.50) on exercise date and actual value at subsequent sale. If you sell on same day as exercise, only income tax is due, since there is no taxable gain.
As the company is private , it may be difficult to sell a small tranch of shares on the secondary market. That might explain the difference between the valuation price offered to new investors and the fair market price if you tried to sell a small tranche.
Good luck for a successful IPO; it's sure to be an interesting one if it's the company I'm thinking of.