Tracfone query, please?

I see where Als & KentE have been discussing a couple of great TF LG phone deals here...and it is the activation part of it that interests me more than the phones - hence my query.

I'm hoping that one of the folks here who knows this stuff really well will set me straight on this, please.

My partner has (for GSM) an LG306G - which is a sub-smartphone that runs a version of Android so poorly lobotomized that the surgeon clearly ONLY had a bent, rusty old spoon as his scalpel.
She hates it & will barely use it unless she's desperate & has ZERO signal on her Twigby phone.

I suspect it will at some point have a fortuitous (for her...) 'accident'.

Knowing this - and that I'll be lucky to rescue so much as its SIM afterwards, I was in the right place & time to grab a final closeout on a Huawei thing for like $5 that is not rootable, but can be used for someone who is hard on such things without worrying if/when it may get killed off.

Finally, my query:
If I grabbed a TF deal for an LG phone with the year card AND wanted to activate that card on the Huawei phone AND use her existing number from the 306g - would that work & any ideas to share of the 'how' for it ??

Thanks for any helpful replies !!