If my wife did not insist on our have a landline/VOIP number we would just use our mobiles, for which we have £5 per month sim only deals that provide us with unlimited calls and unlimited texts with a small amount of mobile data, (that we keep switched off and we never use), for just £5 per month for each sim card.
Personally, for mobile use, I use a Google Pixel 7 Pro phone which has a large easy to see screen and I keep it inside a PVC Flip cover so I dropped it without any issue. (I could if I wished to link it to make/receive VOIP calls and I could instruct it to make calls via voice command by just pressing the Mic Icon and telling it to call someone in the contacts list).
Don't forget that she may also be able to use her tablet, (eg. and IPAD), to make facetime calls.
Also with VOIP it should be noted that if the power goes off the phone goes off so you may want add an uninterruptible power supply if you go down the VOIP route.
With regard to VOIP Providers: personally, I tend to prefer to separate the VOIP providers from the Broadband Providers as changing one service does not then require you to change the other.
For Broadband FTTP we use BT and for VOIP we use two VOIP Providers which are; Sipgate, (no monthly fee but no longer available to new customers), and Voipify which costs us £5.40, (including VAT), per month with 200 minutes of free 01 and 02 calls per month included.
https://www.voipify.net/?mtm_cid=235201820&mtm_kwd=&...
After that the call charge per minute is quite good:
https://www.voipify.net/call-charges/
Regarding, phones we use a Gigaset N300A Base station and we have six Gigaset C575a Dect Phones and the system works great with no issues.
Regarding keeping the old landline number; when we changed to VOIP we just took up one of the local VOIP phone numbers that were free to add and this meant that we could set up the VOIP line while the old landline was still operational and all of the nuisance calls, (solar panel sales etc.), that the old landline number periodically suffered from all disappeared.
Edited by Fido (Mon 08-Jun-26 06:28:17)