Elder DD is studying Arabic plus a humanities subject at Edinburgh and has friends who are studying Arabic + Spanish. She applied for French + Arabic but switched after sitting her A levels.
It’s definitely an achievable combination. Elder DD’s offer from Edinburgh was ABB. It can be hard to get offers from the Scottish unis generally but modern language courses are not very competitive so it’s great if that’s what your DC is interested in. (I studied MFL at uni centuries ago also, including starting a new language, which Arabic is for DD).
Elder DD has loved the Arabic teaching at Edinburgh and is now on her 3rd year abroad.
Younger DD is starting Arabic + a different humanities subject at Durham this autumn. Her subject combo is strangely hard to achieve and she had to apply through the Liberal Arts rubric but that won’t be an issue for your DD. She’s not there yet so I can’t comment on the teaching yet but the open day taster sessions were great.
Elder DD liked Durham a lot too and got an offer (AAA) but she had a slight preference for Edinburgh and the offer felt more comfortable so she firmed Edinburgh.
Exeter is also very strong for Arabic and both DDs really liked Exeter and got offers from there also but for various reasons the Exeter offering didn’t work. Be aware that Exeter sends its Arabic students away in the second year not the third so it’s worth your DD finding out how that could be co-ordinated with spending time in a Spanish-speaking country but elder DD got an offer for Arabic and French so they obviously can make it work.
You could also look at Leeds, Manchester and Warwick, and Oxbridge if that’s a possibility (my DDs weren’t Oxbridge candidates). From memory, there are about a dozen unis that offer Arabic and i’m sure it will be possible to combine it with Spanish at all of those.
Sorry for the lecture - it’s just that we’ve done a similar journey in our family twice in the last few years.