I, for one, am not worried -- at least not yet. Players leave teams for all kinds of reasons that aren't the fault of the club. Turner wants to go somewhere that she'll get more playing time, and Naalsund (predictably) wants to join her. That all makes good sense, especially for players who are probably past their prime. We will miss Turner's big personality, but it won't be a huge loss on the field since neither she nor Naalsund was likely to be a regular starter for us.
Malard says she's "ready for a new challenge" (which I interpret to mean "win the Champions League") but she also seems keen on reuniting with her former coach at Lyon, with whom she reportedly has remained friends. At least our club learned a lesson from the Russo disaster and got a hefty transfer fee out of this, rather than having her leave at the end of next season for free. On the field, we have too many strikers (which I think is Malard's best position) since bringing in Schuller and Wangerheim, so losing Malard isn't as big a loss as it otherwise would be. It does make it more important that we hold onto Terland, though.
The transfer window is open for another 6 weeks, so I think it's too early to panic. The club made some great signings last year and I'm (cautiously) optimistic that they will so again.