My guess is the transaction you describe will not work.
Skrill only recently started offering services to the US. I believe it only non-
gambling only and not sure if peer to peer transfers are available yet. Types of transactions also varies from State to State. I only saw a few posts from US accounts holders depositing to their Skrill from Credit Card and complaining about high fees.
It is probably best to check with Skrill support use the Contact US link found on left hand side when logged into your account.
An alternative method to complete your transaction that work would be to take your Skrill funds and convert it into Bitcoin [Some countries you can do it right from Skrill]. You can then transfer/trade Bitcoin to CashApp or
paypal which you can then send to her.