I'll be very mischievous/anxious about your well-being

[Silverobama]

Hi,

My girlfriend told me (now we are not living in the same city) she would attend an English speech competition in city B and stay there for two days alone. I asked her to keep in touch with me and she asked me why, I said:

I'll be very mischievous/anxious about your well-being.

The intended meaning is "I'll be very worrying about your safety when you're in another city because you're so young".

Is the italic sentence good?

 

[Tarheel]

I wouldn't use "mischievous". That's for sure.

You could say you're concerned about her safety.

Do NOT say you'll be very worrying.

You could say you'll be worried.

You might say you want to be sure she's OK.

You could say you care about her, and you want to be sure she's safe.

 

[tedmc]

Take care. Stay safe.

 

[Silverobama]

Take care. Stay safe.

But I want her to know that I am worried about her safety.

 

[Rover_KE]

Well say so.

I can’t understand why you think ‘mischievous’ has any meaning here.

 

[Tarheel]

But I want her to know that I am worried about her safety.

That's almost right. You are worried about her and concerned for her safety.

I don't know what your relationship is, but I do know that what you say to her has to -- at least in part -- depend on that.

 

[emsr2d2]

Hi.

My girlfriend told me (now we are not living no longer live in the same city and she recently told me she would attend will be attending an English speech speaking competition in city B [name of city] and stay will be there alone for two days. alone. I asked her to keep in touch with me during her trip and she asked me why. I said:

I'll be very mischievous/ anxious about your well-being.

The intended meaning is "I'll be very worrying worried about your safety when you're in another city there because you're so young".

Is the italic sentence good?

Note my corrections above.
(Non-language-related - I really don't think you should say this to her at all. Saying you're going to be worried for her safety might actually scare her!)