"The model has the pants with her."

Translation: Modellen har med sig byxorna.

[kounsh]

Does "modellen har byxorna med henne" makes sense?

[Arnauti]

No. Har med sig is a reflexive verb. They are used like this:
Jag har med mig
Du har med dig
Hon/han/den/det har med sig
Vi har med oss
Ni har med er
De har med sig
so there is never a case when henne or honom are a part of those verbs.

[kounsh]

so "har med sig" is a verb which is different from the verb "har"?

[Arnauti]

Yes, that's right!

[Coreopsis2943]

And it means to have with them?

[cynyork]

"modelen har byxorna med sig" - is marked wrong. Can I generalize that all three words always have to stick together ?

[Arnauti]

No, Modellen har byxorna med sig. is an accepted answer. Don't know what may have happened there.

[cynyork]

oh thanks!